9. Fish and Shellfish Ecology

9.1.        Introduction

9.1. Introduction

1. This chapter of the Offshore Environmental Impact Assessment (EIA) Report presents the assessment of the likely significant effects (as per the “EIA Regulations”) on the environment of the Berwick Bank Wind Farm offshore infrastructure which is the subject of this application (hereafter referred to as “Proposed Development”) on fish and shellfish ecology. Specifically, this chapter considers the potential impacts of the Proposed Development seaward of Mean High Water Springs (MHWS) during the construction, operation and maintenance, and decommissioning phases.
2. Likely significant effect is a term used in both the “EIA Regulations” and the Habitat Regulations. Reference to likely significant effect in this Offshore EIA Report refers to “likely significant effect” as used by the “EIA Regulations”. This Offshore EIA Report is accompanied by a Report to Inform Appropriate Assessment (RIAA) (SSER, 2022c) which uses the term as defined by the Habitats Regulations Appraisal (HRA) Regulations.
3. The assessment presented is informed by the following technical chapters and appendices:

• volume 3, appendix 7.1: Physical Processes Technical Report;
• volume 2, chapter 8: Benthic Subtidal and Intertidal Ecology;
• volume 3, appendix 8.1: Benthic Subtidal and Intertidal Ecology Technical Report;
• volume 3, appendix 9.1: Fish and Shellfish Ecology Technical Report;
• volume 2, chapter 10: Marine Mammals;
• volume 3, appendix 10.1: Subsea Noise Technical Report;
• volume 2, chapter 11: Offshore and Intertidal Ornithology; and
• volume 3, appendix 12.1: Commercial Fisheries Technical Report.
  4. This chapter summarises information contained within volume 3, appendix 9.1. The technical report provides a detailed characterisation of the fish and shellfish ecology present in the northern North Sea and within the fish and shellfish ecology study area, as presented within section 9.3. This characterisation is based on existing literature sources and site specific surveys, which provide information on the fish and shellfish assemblages present within clearly defined study areas (as described in section 9.3), and the identification and valuation of fish and shellfish receptors (i.e. Important Ecological Features (IEFs); see section 9.7.3 relevant to the fish and shellfish ecology assessment.

9.2.        Purpose of this Chapter

9.2. Purpose of this Chapter

5. The primary purpose of the Offshore EIA Report is outlined in volume 1, chapter 1. It is intended that the Offshore EIA Report will provide the Scottish Ministers, statutory and non-statutory stakeholders with sufficient information to determine the likely significant effects of the Proposed Development on the receiving environment.
6. In particular, this Fish and Shellfish Ecology EIA Report chapter:

• presents the existing environmental baseline established from desk studies, site-specific surveys and consultation with stakeholders;
• identifies any assumptions and limitations encountered in compiling the environmental information;
• presents the likely significant environmental impacts on fish and shellfish ecology arising from the Proposed Development and reaches a conclusion on the likely significant effects on fish and shellfish ecology, based on the information gathered and the analysis, assessments and (where relevant) modelling undertaken; and
• highlights any necessary monitoring and/or mitigation measures which are recommended to prevent, minimise, reduce or offset the likely significant adverse environmental effects of the Proposed Development on fish and shellfish ecology.
  7. Impacts on commercial fisheries are considered separately to fish and shellfish ecology in volume 2, chapter 12.

9.3.        Study Area

9.3. Study Area

8. Fish and shellfish are spatially and temporally variable, therefore for the purposes of the fish and shellfish ecology characterisation, two study areas are defined. These are shown in Figure 9.1   Open ▸ and described here, as agreed with stakeholders through consultation (see section 9.5):

• The Proposed Development fish and shellfish ecology study area has been defined with reference to the Proposed Development boundary that existed prior to the boundary refinement in June 2022. As the refinement resulted in a reduction of the Proposed Development array area, the fish and shellfish ecology study area is considered to present a conservative baseline against which the fish and shellfish assessment is undertaken. The Proposed Development fish and shellfish ecology study area has not therefore been realigned to the current Proposed Development boundary.
• The Proposed Development northern North Sea fish and shellfish ecology study area encompasses the Proposed Development fish and shellfish ecology study area and a surrounding area defined by the boundary of the northern North Sea as defined by the biogeographic region identified as part of the Review of Marine Nature Conservation (RMNC) (2004). This is the regional study area and also encompasses waters of the Forth and Tay Scottish Marine Region (SMR). The Proposed Development northern North Sea fish and shellfish ecology study area provides a wider context for the fish and shellfish species and populations identified within the Proposed Development fish and shellfish ecology study area and will inform assessments of those impacts affecting fish and shellfish receptors over a larger scale (e.g. underwater noise).
  9. The offshore topic of Proposed Development fish and shellfish ecology study area includes the intertidal area. This intertidal area overlaps with the onshore topics of ecology and ornithology. Impacts on fish and shellfish receptors in the intertidal area have been scoped out from the assessment (see volume 3, appendix 9.1 and Table 9.16   Open ▸ ) as agreed with stakeholders ( Table 9.8   Open ▸ ).

Figure 9.1: Proposed Development Fish and Shellfish Ecology Study Area

9.4.        Policy and Legislative Context

9.4. Policy and Legislative Context

10. Policy and legislation on renewable energy infrastructure is presented in volume 1, chapter 2 of the Offshore EIA Report. Policy and legislation specifically in relation to fish and shellfish ecology, is contained in the Marine (Scotland) Act 2010, the Marine and Coastal Access Act (MCAA) 2009, the Habitats Regulations, Scotland’s National Marine Plan, The Sectoral Marine Plan and the UK Marine Policy Statement. A summary of the legislative provisions relevant to fish and shellfish ecology are provided in Table 9.1   Open ▸ to Table 9.3   Open ▸ , with other relevant policy provisions set out in Table 9.4   Open ▸ to Table 9.7   Open ▸ .
11. All the policy and legislation provided in Table 9.1   Open ▸ to Table 9.7   Open ▸ is also relevant to the intertidal area.

Table 9.1: Summary of Marine (Scotland) Act 2010 Relevant to Fish and Shellfish Ecology

Table 9.2: Summary of Marine Coastal Access Act 2009 Relevant to Fish and Shellfish Ecology

Table 9.3: Summary of the Habitats Regulations Relevant to Fish and Shellfish Ecology

Table 9.4: Summary of Scotland’s National Marine Plan Relevant to Fish and Shellfish Ecology

Table 9.5: Summary of Scottish Priority Marine Features (NatureScot, 2020) Relevant to Fish and Shellfish Ecology

Table 9.6: Summary of The Sectoral Marine Plan for Offshore Wind Energy 2020 Relevant to Fish and Shellfish Ecology

Table 9.7: Summary of the UK Marine Policy Statement Relevant to Fish and Shellfish Ecology

9.5.        Consultation

9.5. Consultation

12. The Fish and Shellfish Ecology Road Map was a ‘live’ document which has been used as a tool to facilitate early engagement with stakeholders and subsequent engagement throughout the pre-application phase of the Proposed Development including on reaching points of agreement on scoping impacts out of the assessment, and/or agreeing the level of assessment which will be presented for impacts, so that the focus in the EIA Report is on likely significant environmental effects as defined by the EIA Regulations.
13. The Fish and Shellfish Ecology Road Map (up to date at the point of Application) is presented as volume 3, appendix 8.2 and documents meetings and discussion points. At the request of MS-LOT[1] an audit document (the Berwick Bank Wind Farm Audit Document for Post-Scoping Discussions (volume 3, appendix 5.1) has been produced and submitted alongside the application to document discussions on key issues, post-receipt of the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022).
14. A summary of the key issues raised during consultation activities undertaken to date specific to fish and shellfish ecology is presented in Table 9.8   Open ▸ , together with how these issues have been considered in the production of this Fish and Shellfish Ecology EIA Report chapter. Further detail is presented within volume 1, chapter 5.

Table 9.8: Summary of Key Consultation of Relevance to Fish and Shellfish Ecology

9.6.        Methodology to Inform Baseline

9.6. Methodology to Inform Baseline

9.6.1.    Desktop Study

15. Information on fish and shellfish ecology within the Proposed Development fish and shellfish ecology study area and Proposed Development northern North Sea fish and shellfish ecology study area was collected through a detailed desktop review of existing studies and datasets. These are summarised in Table 9.9   Open ▸ with full details presented in the technical report. Other studies considered as part of the baseline characterisation, although not included in this table, are fully detailed and discussed in volume 3, appendix 9.1.

Table 9.9: Summary of Key Desktop Reports Identified in Scoping Report and Scoping Opinion

9.6.2.    Identification of Designated Sites

16. All relevant designated sites within the northern North Sea fish and shellfish ecology study area and qualifying interest features that could be affected by the construction, operation and maintenance, and decommissioning phases of the Proposed Development were identified using the three-step process described here:

• Step 1: All designated sites of international, national and local importance within the Proposed Development northern North Sea fish and shellfish ecology study area were identified using a number of sources. These sources included Joint Nature Conservation Committee (JNCC), MPA mapper, and the Marine Scotland National Marine Plan Interactive (NMPI) maps.
• Step 2: Information was compiled on the relevant features for each of these sites (e.g. species listed as features of the relevant designated sites, information on habitat usage, migration information etc.).
• Step 3: Using the above information and expert judgement, sites were included for further consideration if:

–      a designated site directly overlaps with the Proposed Development;

–      sites and associated features were located within the potential Zone of Influence (ZoI) for impacts associated with the Proposed Development; and

–      sites which are designated to protect mobile features (e.g. diadromous fish) and where the range of those features has the potential to overlap with either the Proposed Development and/or the ZoI of impacts associated with the development (e.g. fish migrating through or close to the Proposed Development at particular life history stages).

17. Identified designated sites are listed in Table 9.12   Open ▸ .

9.6.3.    Site-Specific Surveys

18. A site specific benthic sub-tidal survey was completed in 2020. Data collected as part of this survey has been used to inform this Fish and Shellfish Ecology EIA Report chapter, as agreed with MS-LOT, MSS and NatureScot via the Road Map process (see Table 9.10   Open ▸ and volume 3, appendix 9.1 for further details). Further information about this site specific survey is provided in Table 9.10   Open ▸ below.

Table 9.10: Summary of Site-Specific Survey Data

9.7.        Baseline Environment

9.7. Baseline Environment

9.7.1.    Overview of Baseline Environment

19. The baseline environment has been described in detail within volume 3, appendix 9.1. The fish and shellfish receptors that could be potentially impacted by the Proposed Development have been determined by the desktop review of available data/information as detailed in Table 9.9   Open ▸ , and through site-specific surveys, as detailed in Table 9.10   Open ▸ (see volume 3, appendix 9.1 for further detail regarding baseline data collection and site specific surveys). Through this process a number of demersal, pelagic, elasmobranch and diadromous fish species were identified, along with shellfish species. The baseline environment was described for the Proposed Development northern North Sea fish and shellfish ecology study area and for the Firth and Tay SMR. Spawning and nursery areas within the vicinity of the Proposed Development fish and shellfish ecology study area were also described, followed by detailed characterisations of particularly sensitive fish and shellfish species, including sandeel, herring (focussing on spawning habitats) and diadromous fish species.
20. Species identified as likely to be found within the Proposed Development northern North Sea fish and shellfish ecology study area include:

• demersal species – sandeel, whiting Merlangius merlangus, lemon sole Microstomus kitt, ling Molva molva, plaice Pleuronectes platessa, saithe Pollachius virens and cod Gadus morhua;
• pelagic species – herring, mackerel Scomber scombrus and sprat Sprattus sprattus;
• elasmobranch species – spotted ray Raja montagui, spurdog Squalus acanthias, tope Galeorhinus galeus common skate Dipturus batis, and thornback ray Raja ecommi. Basking sharks Cetorhinus maximus are likely to pass through the vicinity of the Proposed Development fish and shellfish ecology study area but infrequently and in low numbers;
• diadromous species – Atlantic salmon, European eel Anguilla ecommis, sea trout, river lamprey, sea lamprey, Allis shad, Alosa alosa, twaite shad Alosa fallax, sparling/European smelt Osmerus eperlanus; and freshwater pearl mussel Margaritifera margaritifera (included here due to reliance on Atlantic salmon and sea trout at specific life stages); and
• shellfish species – Nephrops, European lobster Homarus ecommis, crab (edible (brown) crab Cancer pagarus and velvet swimming crab Necora puber), king scallop Pecten maximus, and squid Loligo sp.
  21. The spawning and nursery habitats present in the Proposed Development fish and shellfish ecology study area are summarised in Table 9.11   Open ▸ based on Ellis et al. (2012) and Coull et al. (1998). Nursery and spawning habitats were categorised by Ellis et al. (2012) as either high or low intensity dependent on the level of spawning activity or abundance of juveniles recorded. Spawning grounds identified by Coull et al. (1998) are classified as low, high or undetermined, again based on the level of spawning activity. Intensity of nursery grounds were not specified by Coull et al. (1998). Further detail on nursery and spawning grounds is presented in volume 3, appendix 9.1.
  22. However, due to the particular sensitivities of herring and sandeel to offshore wind development (including underwater noise and seabed disturbance), a summary of the baseline characterisation presented in volume 3, appendix 9.1 has been included in the following section.

Table 9.11: Species Known to Have Spawning and Nursery Areas that Overlap with the Proposed Development Fish and Shellfish Ecology Study Area and Spawning Periods (Coull et al., 1998, Ellis et al., 2010) (see volume 3, appendix 9.1)

Herring

23. Herring utilise specific benthic habitats during spawning, which increases their vulnerability to activities impacting the seabed. Further, as a hearing specialist, herring are vulnerable to impacts arising from underwater noise. Herring spawning grounds have been identified by Coull et al. (1998) as being present within the Proposed Development fish and shellfish ecology study area. However, data presented by Coull et al. (1998) is relatively broad scale, and therefore, confidence in the presence of spawning grounds can be increased through completing spawning assessments using larval data available from IHLS.
24. The IHLS conducts monitoring where larvae numbers are recorded around the UK coastline and the North Sea. Herring larvae are identified as being recently hatched by their size, and therefore small herring larvae can be assumed to have been spawned recently and therefore in close proximity to the area where they are recorded. The IHLS present larval data by size per m2, with larvae under 10 mm long used as a cut off point for recently spawned larvae. Recently spawned larvae will not have drifted far from the location where eggs were spawned on the seabed and high abundances of these larvae are therefore a good indication of recent spawning activity local to where these were sampled.
25. Figure 9.2   Open ▸ provides a composite of the individual years of herring larval data from the IHLS for the years 2007 to 2016 (see volume 3, appendix 9.1 for individual years). This shows where highest numbers of herring larvae were consistently recorded over a ten-year period, using a cut off of 100 larvae <10 mm in length per m2. Areas marked with darker blue patches indicate where spawning evidence (i.e. high abundances of larvae) was most regularly recorded and therefore indicates the core spawning habitat for the Buchan herring spawning stock. As shown in Figure 9.2   Open ▸ , there is a large patch of darker blue to the north of the Proposed Development which corresponds with the annual herring larval data high density areas. The Proposed Development fish and shellfish ecology study area and the area to the south is marked as lighter blue which reflects less consistent, more variable spawning activity.
26. The larval density data supports the Coull et al. (1998) data, showing significant spawning areas to the north of the Proposed Development fish and shellfish ecology study area, and also to the far south. However, it also slightly contradicts Coull et al. (1998) as the spawning areas identified which overlap the Proposed Development export cable corridor have not been demonstrated to have consistently high herring spawning activity (this area was characterised by muddy sediments which are unsuitable for herring spawning). This is further supported by results from detailed site specific survey PSA data (see volume 3, appendix 9.1 for full results) which found that the majority of the Proposed Development fish and shellfish ecology study area has unsuitable sediment for herring spawning, with only small patches of suitable habitat in the north-west section of the Proposed Development array area. By contrast, the core herring spawning area shown in Figure 9.2   Open ▸ coincided with areas of suitable herring spawning habitat (i.e. coarse, gravelly sediments) which is shown in Figure 9.3   Open ▸ ; see volume 3, appendix 9.1 for full details).

Figure 9.2: Herring Larval Density of over 100 per m2 per Year from 2007 to 2016

Figure 9.3: Herring Spawning Habitat Preference Classifications from EMODnet and Site-Specific Survey Data Covering the Buchan Stock Herring Spawning Habitats

Sandeel

27. Sandeel high intensity spawning grounds have been identified by Ellis et al. (2012) as being present throughout the Proposed Development fish and shellfish ecology study area. However, data presented by Ellis et al. (2012) is relatively broad scale, and therefore, confidence in the presence of spawning grounds can be increased through completing analysis on site specific surveys and drawing on more recently published data which can provide increased data resolution.
28. Figure 9.4   Open ▸ presents the results of site-specific PSA survey data alongside European Marine Observation and Data Network (EMODnet) seabed substrate data which can be used to assess habitat suitability for sandeel. For the purposes of considering sandeel habitat, suitability across the Proposed Development fish and shellfish ecology study area and surrounding areas, gravelly sand, (gravelly) sand, and sand in the EMODnet data were classified as preferred habitat and sandy gravel as marginal habitat (see volume 3, appendix 9.1 for further details). Where no shading is present, the habitat in that area is unsuitable for sandeel. Results of PSA were categorised into prime, subprime, suitable and unsuitable, dependant on the proportion of sand and mud in grab samples. On the whole, there is good alignment between the results of site-specific surveys and EMODnet seabed substrate data with the Proposed Development array area containing mostly preferable habitat with a few patches of marginal habitat. The Proposed Development export cable corridor has a significant patch of unsuitable habitat, which matches PSA points of unsuitable habitat, although there are some misalignments within the Proposed Development export cable corridor, where the EMODnet data suggests suitable habitat, but the PSA data indicates the opposite. PSA data is of higher resolution and therefore supersedes the EMODnet data. The Proposed Development export cable corridor has been found to be dominated by muddy sediments, which further supports the site-specific survey results, which determine much of the Proposed Development export cable corridor as unsuitable (see volume 3, appendix 9.1 for further detail). The site-specific survey results provide higher resolution of favourable sandeel habitat, which generally shows that the Proposed Development array area is favourable sandeel habitat, and the Proposed Development export cable corridor is less favourable to unsuitable sandeel habitat.
29. Further work regarding sandeel has been completed by Langton et al. (2021) where a predicted distribution model for sandeel was developed, producing predicted density and probability of occurrence for sandeel around the British coastline. This modelling was undertaken based on the dependence of sandeel on particular habitat types, with the four main explanatory variables within the model being silt, depth, sand and slope, and was supported by sandeel fisheries data (e.g. data from Jensen et al., 2011). The results were mapped, highlighting areas of importance for sandeel populations in the North Sea, including the Forth and Tay SMR and the Proposed Development fish and shellfish ecology study area. Figure 9.5   Open ▸ presents the outputs of the modelling within the Proposed Development. This identifies a number of areas within the Proposed Development array area where there is a high probability of sandeel presence. However, predicted densities of sandeel are more variable with areas of predicted lower sandeel densities interspersed with discrete patches of predicted higher sandeel density. These areas also correlate to previous studies where marine mammals and birds are known to congregate and feed on sandeel (Langton et al., 2021). This supports results of habitat suitability characterisation from site specific surveys, further depicting the suitability of habitat within the Proposed Development array area for sandeel and that the Proposed Development export cable corridor is less suitable or unsuitable.

Figure 9.4: Sandeel Habitat Preference Classifications from EMODnet and Site-specific Survey Data

Figure 9.5: Model Derived Predictions of Density and Probability of Presence of Sandeel within the Proposed Development (derived from Langton et al. (2021))

9.7.2.    Designated Sites

30. Designated sites identified for consideration within the Fish and Shellfish Ecology EIA Report chapter are described in Table 9.12   Open ▸ .

Table 9.12: Designated Sites with Relevant Qualifying Interest Features for the Fish and Shellfish Ecology EIA Report Chapter

9.7.3.    Important Ecological Features

31. IEFs are habitats, species, ecosystems and their functions/processes that are considered to be important and potentially impacted by the Proposed Development. As agreed by stakeholders, guidance from the Chartered Institute of Ecology and Environmental Management (CIEEM) (2019) was used to assess IEFs. IEFs can be attributed to individual species (such as plaice) or species groups (for example other flat fish species). Each IEF is assigned a value or importance rating which is based on commercial, ecological and conservation importance. In particular, and following stakeholder responses to the Scoping Report (see Table 9.8   Open ▸ ), IEF importance ratings have considered whether fish and shellfish IEFs have been identified as PMFs in Scottish waters and/or whether these are qualifying features of SACs. Table 9.13   Open ▸ details the criteria used for determining IEFs and Table 9.14   Open ▸ presents the defining characteristics for classification of IEFs, providing justifications for importance rankings for the key species likely to occur within the Proposed Development fish and shellfish ecology study area. Specific reference is made to each species’ commercial, conservation and ecological importance, where this is known. These species will be taken forward for assessment. Diadromous species refer to specific species that migrate between fresh water and the marine environment (see Table 9.14   Open ▸ ). Marine fish and shellfish species refer to all other IEF species identified within this chapter ( Table 9.14   Open ▸ ). Within the individual assessments of effects, diadromous fish and marine fish are considered separately following stakeholder feedback (see Table 9.8   Open ▸ ).

Table 9.13: Defining Criteria for IEFs

Table 9.14: IEF Species and Representative Groups within the Proposed Development Fish and Shellfish Ecology Study Area

9.7.4.    Future Baseline Scenario

32. The EIA Regulations ((The Electricity Works (Environmental Impact Assessment) (Scotland) Regulations 2017, The Marine Works (Environmental Impact Assessment) (Scotland) Regulations 2017; The Marine Works (Environmental Impact Assessment) Regulations 2007; and The Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations, 2017)), require that a “a description of the relevant aspects of the current state of the environment (baseline scenario) and an outline of the likely evolution thereof without development as far as natural changes from the baseline scenario can be assessed with reasonable effort ,on the basis of the availability of environmental information and scientific knowledge” is included within the Offshore EIA Report.
33. In the event that the Proposed Development does not come forward, an assessment of the future baseline conditions has been carried out and is described within this section.
34. The baseline environment is not static and will exhibit some degree of natural change over time, even if the Proposed Development does not come forward, due to naturally occurring cycles and processes and additionally any potential changes resulting from climate change. Therefore, when undertaking assessments of effects, it will be necessary to place any potential impacts into the context of the envelope of change that might occur over the timescale of the Proposed Development.
35. Further to potential change associated with existing cycles and processes, it is necessary to take into account the potential effects of climate change on the marine environment. Variability and long-term changes on physical influences may bring direct and indirect changes to fish and shellfish populations and communities in the mid to long term future (Heath et al., 2012).
36. Scottish and UK waters are facing an increase in sea surface temperature. The rate of increases is varied geographically, but between 1985 and 2009, the average rate of increase in Scottish waters has been greater than 0.2 °C per decade, with the south-east of Scotland having a higher rate of 0.5°C per decade (Marine Scotland, 2011). A study completed over a longer period of time showed Scottish waters (coastal and oceanic) have warmed by between 0.05 and 0.07 °C per decade, calculated across the period 1870 – 2016 (Hughes et al., 2018). Changes in temperature will have an effect on fish at all biological levels (cellular, individual, population, species, community and ecosystem) both directly and indirectly. As sea temperatures rise, species adapted to cold water (e.g. cod and herring) will begin to disappear while warm water adapted species will become more established. It is also predicted that due to changes in weather patterns, for example increased numbers of spring storms, changes in stratification of water columns and plankton production may occur (Morison et al., 2019). This may cause knock on impacts on fish and shellfish species due to changes in food availability for prey species. Climate change presents many uncertainties as to how the marine environment will change in the future; therefore, the future baseline scenario is difficult to predict with accuracy.
37. Any changes that may occur during the design life span of the Proposed Development should be considered in the context of both greater variability and sustained trends occurring on national and international scales in the marine environment.

9.7.5.    Data Limitations and Assumptions

38. The data sources used in this chapter are detailed in Table 9.9   Open ▸ and volume 3, appendix 9.1. The desktop data used are the most up to date publicly available information which can be obtained from the applicable data sources as cited. Data that have been collected is based on existing literature, consultation with stakeholders and identification of habitats to inform likely fish and shellfish species.
39. Site-specific surveys were carried out for benthic ecology requirements (volume 2, chapter 8), therefore were not specifically targeting fish and shellfish species, and therefore some species may have been missed. However, commercial fisheries information has been incorporated into the baseline characterisation, which itself was informed by consultation with the fishing industry, as presented in volume 2, chapter 12. As such, this additional information will have filled any gaps missed through site-specific survey. These surveys provided opportunistic additional fish and shellfish data which has been incorporated into the assessment. However, given the detailed desktop study completed, covering a long time series and a wide variety of information sources (e.g. including scientific literature, grey literature, commercial fisheries information) and the conservative approach adopted, which has included identification of a regional study area (i.e. the Proposed Development northern North Sea fish and shellfish ecology study area), it is unlikely that key species have been omitted from the assessment.

9.8.        Key Parameters for Assessment

9.8. Key Parameters for Assessment

9.8.1.    Maximum Design Scenario

40. The maximum design scenarios identified in Table 9.15   Open ▸ have been selected as those having the potential to result in the greatest effect on fish and shellfish IEFs. These scenarios have been selected from the details provided in volume 1, chapter 3 of the Offshore EIA Report. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the Project Design Envelope (PDE) (e.g. different infrastructure layout), to that assessed here, be taken forward in the final design scheme.

Table 9.15: Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Effects on Fish and Shellfish Ecology

9.8.2.    Impacts Scoped out of the Assessment

41. The Fish and Shellfish Ecology Road Map (volume 3, appendix 8.2), the Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a) and the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022) (see section 9.5), have been used to facilitate stakeholder engagement on topics to be scoped out of the assessment.
42. On the basis of the baseline environment and the project description outlined in volume 1, chapter 3 of the Offshore EIA Report, a number of impacts are proposed to be scoped out of the assessment for fish and shellfish ecology. These have been agreed with key stakeholders through consultation as discussed in volume 1, chapter 5. Otherwise, these impacts were proposed to be scoped-out in The Berwick Bank Wind Farm Offshore Scoping Report (SSER, 2021a) and no concerns were raised by key consultees. Where discussions with consultees took place after the publication of the Berwick Bank Wind Farm Scoping Opinion (MS-LOT, 2022), these are audited in the Berwick Bank Wind Farm Audit Document for Post-Scoping Discussions (volume 3, appendix 5.1).
43. Following consultation with stakeholders and advice received within the Offshore EIA Scoping Opinion (Marine Scotland, 2021), it has been agreed to scope these impacts out for further consideration within the EIA for fish and shellfish ecology.
44. These impacts are outlined, together with a justification for scoping them out, in Table 9.16   Open ▸ .

Table 9.16: Impacts Scoped Out of the Assessment for Fish and Shellfish Ecology (tick confirms the impact is scoped out)

9.9.        Methodology for Assessment of Effects

9.9. Methodology for Assessment of Effects

9.9.1.    Overview

45. The fish and shellfish ecology assessment of effects has followed the methodology set out in volume 1, chapter 6 of the Offshore EIA Report. Specific to the fish and shellfish ecology EIA, the following guidance documents have also been considered:

• Guidelines for Ecological Impact Assessment (EcIA) in the UK and Ireland. Terrestrial, Freshwater and Coastal (CIEEM, 2019);
• Guidance on Environmental Considerations for Offshore Wind Farm Development (OSPAR, 2008); and
• Guidelines for data acquisition to support marine environmental assessments of offshore renewable energy projects (Judd, 2012).
  46. In addition, the fish and shellfish ecology assessment of effects has considered the legislative framework as set out in volume 1, chapter 2 of the Offshore EIA Report.

9.9.2.    Criteria for Assessment of Effects

47. The process for determining the significance of effects is a two-stage process that involves defining the magnitude of the potential impacts and the sensitivity of the receptors. This section describes the criteria applied in this chapter to assign values to the magnitude of potential impacts and the sensitivity of the receptors. The terms used to define magnitude and sensitivity are based on those which are described in further detail in volume 1, chapter 6 of the Offshore EIA Report.
48. The criteria for defining magnitude in this chapter are outlined in Table 9.17   Open ▸ . In determining magnitude within this chapter, each assessment considered the spatial extent, duration, frequency and reversibility of impact and these are outlined within the magnitude section of each assessment of effect (e.g. a duration of hours or days would be considered for most receptors to be of short term duration, which is likely to result in a low magnitude of impact).

Table 9.17: Definition of Terms Relating to the Magnitude of an Impact

49. The definitions of sensitivities of fish and shellfish IEFs have been informed by the Marine Evidence based Sensitivity Assessment (MarESA) (MarLIN, 2021) and Feature Activity Sensitivity Tool (FeAST) (NatureScot, 2021). The MarESA defines sensitivity as a product of the likelihood of damage (resistance) due to a pressure and the rate of recovery (recoverability) once the pressure has been removed. Recoverability is the ability of a habitat to return to the state of the habitat that existed before the activity or event which caused change. Full recovery does not necessarily mean that every component species has returned to its prior condition, abundance, or extent but that the relevant functional components are present, and the habitat is structurally and functionally recognisable as the initial habitat of interest. The FeAST is another web based application which allows users to investigate the sensitivity of marine features in Scotland's seas, to pressures arising from human activities (noting that this has been developed for features of low/limited mobility, so may not be relevant to fish and shellfish ecology). The FeAST sensitivity assessment considers feature tolerance (ability to absorb or resist change or disturbance) to a pressure and its ability to recover once the pressure stops. Both the MarESA and the FeAST define pressures by a benchmark which describes the extent and duration of the pressure but does not consider the intensity, frequency of pressures or any cumulative impacts. The FeAST tool has been utilised to identify pressures where possible, however, it is only available for a small number of fish and shellfish species at the time of writing.
50. The sensitivities of fish and shellfish IEFs presented within this EIA Report have therefore been defined by an assessment of the combined vulnerability (i.e. resistance, following MarESA, or tolerance following FeAST) of the receptor to a given impact and the likely rate of recoverability to pre-impact conditions (consistent with both MarESA and FeAST). Here, vulnerability is defined as the susceptibility of a species to disturbance, damage or death, from a specific external factor. Recoverability is the ability of the same species to return to a state close to that which existed before the activity or event which caused change. Recoverability is dependent on an IEFs ability to recover or recruit subject to the extent of disturbance/damage incurred. Information on these aspects of sensitivity of the fish and shellfish IEFs to given impacts has been informed by the best available evidence following environmental impact or experimental manipulation in the field and evidence from the offshore wind industry and analogous activities such as those associated with aggregate extraction, electrical cabling, and oil and gas industries. These assessments have been combined with the importance of the relevant IEFs as defined in section 9.7.3 and as presented in Table 9.14   Open ▸ for the fish and shellfish IEFs considered in this assessment.
51. The criteria for defining sensitivity in this chapter are outlined in Table 9.18   Open ▸ .

Table 9.18: Definition of Terms Relating to the Sensitivity of the Receptor

52. The significance of the effect upon fish and shellfish ecology is determined by correlating the magnitude of the impact and the sensitivity of the receptor. The particular method employed for this assessment is presented in Table 9.19   Open ▸ .
53. In cases where a range is suggested for the significance of effect, there remains the possibility that this may span the significance threshold (e.g. the range is given as minor to moderate). In such cases the final significance conclusion is based upon the author’s professional judgement as to which outcome delineates the most likely effect. Where professional judgement is applied to quantify final significance from a range, the assessment will set out the factors that result in the final assessment of significance. These factors may include the likelihood that an effect will occur, data certainty and relevant information about the wider environmental context.
54. For the purposes of this assessment:

• a level of residual effect of moderate or more will be considered a ‘significant’ effect in terms of the EIA Regulations; and
• a level of residual effect of minor or less will be considered ‘not significant’ in terms of the EIA Regulations.
  55. Effects of moderate significance or above are therefore considered important in the decision-making process, whilst effects of minor significance or less warrant little, if any, weight in the decision-making process.

Table 9.19: Matrix Used for the Assessment of the Significance of the Effect

9.9.3.    Designated Sites

56. Where Natura 2000 sites (i.e. nature conservation sites in Europe designated under the Habitats or Birds Directives[4]; or sites in the UK that comprise the National Site Network (collectively termed ‘European sites’) are considered, this chapter makes an assessment of the likely significant effects in EIA terms on the qualifying interest feature(s) of these sites as described within section 9.7.2 of this chapter. The assessment of the of the potential impacts on the site itself are deferred to the RIAA (SSER, 2022c) for the Proposed Development. A summary of the outcomes reported in the RIAA is provided in section 9.15 of this chapter.
57. With respect to locally designated sites and national designations (other than European sites), where these sites fall within the boundaries of a European site and where qualifying interest features are the same, only the features of the European site have been taken forward for assessment. This is because potential impacts on the integrity and conservation status of the locally or nationally designated site are assumed to be inherent within the assessment of the features of the European site (i.e. a separate assessment for the local or national site features is not undertaken). However, where a local or nationally designated site falls outside the boundaries of a European site, but within the Proposed Development northern North Sea fish and shellfish ecology study area, an assessment of the likely significant effects on the overall site is made in this chapter using the EIA methodology.

9.10.   Measures Adopted as part of the Proposed Development

9.10. Measures Adopted as part of the Proposed Development

58. As part of the project design process, a number of measures have been proposed to reduce the potential for impacts on fish and shellfish ecology (see Table 9.20   Open ▸ ). As there is a commitment to implementing these measures, they are considered inherently part of the design of the Proposed Development and have therefore been considered in the assessment presented in section 9.11 (i.e. the determination of magnitude and therefore significance assumes implementation of these measures). These measures are considered standard industry practice for this type of development.

Table 9.20: Designed In Measures Adopted as Part of the Proposed Development

9.11.   Assessment of Significance

9.11. Assessment of Significance

59. The potential effects arising from the construction, operation and maintenance and decommissioning phases of the Proposed Development are listed in Table 9.15   Open ▸ , along with the maximum design scenario against which each impact has been assessed. An assessment of the likely significance of the effects of the Proposed Development on fish and shellfish ecology IEFs caused by each identified impact is given below.

Temporary Subtidal Habitat loss/disturbance

60. Direct temporary habitat loss/disturbance of subtidal seabed habitats within the Proposed Development array area and offshore export cable corridor during the construction, operation and maintenance, and decommissioning phases will occur as a result of a range of activities including use of jack-up vessels during foundation installation/maintenance, installation and maintenance of inter-array and offshore export cables (including seabed clearance operations prior to cable installation) and anchor placements associated with these activities. Disturbance to these habitats has the potential to affect identified fish and shellfish IEFs directly (e.g. removal or injury of individuals) and indirectly (e.g. loss of important fish and shellfish habitats, such as spawning grounds).
61. Seabed preparation activities, including sand wave clearance and boulder clearance, will occur in advance of installation of inter-array cables and offshore export cables. Dredged material resulting from seabed preparations will be disposed of within the Proposed Development. The assessment therefore includes habitat loss/disturbance associated with disposal of dredged material from this activity, (i.e. habitat loss/disturbance due to placement of large volumes of coarse sediments on the seabed (see Table 9.15   Open ▸ )). Effects on areas of seabed which have been subject to seabed preparation activities prior to foundation installation have been assessed under long term subtidal habitat loss as the area of seabed affected by seabed preparation will be the same area on which foundations (and potentially scour protection) will be placed for the lifetime of the Proposed Development.

Construction Phase

Magnitude of Impact

62. The installation of infrastructure within the Proposed Development fish and shellfish ecology study area may lead to temporary subtidal habitat loss/disturbance. The maximum design scenario is for up to 113,974,700 m2 of temporary habitat loss/disturbance during the construction phase ( Table 9.15   Open ▸ ). This equates to 9.7% of the Proposed Development, representing a relatively small proportion of the Proposed Development fish and shellfish ecology study area. It should be noted that only a small proportion of the total footprint will be affected at any one time during the 96 months construction phase, with recovery of seabed habitats commencing immediately following installation of infrastructure.
63. Temporary habitat loss of up to 42,948,000 m2 will also occur as a result of the installation of up to 1,225 km of inter-array cables, 94 km of OSP/Offshore convertor substation platform interconnector cables and up to 872 km of offshore export cables. Sand wave clearance may be required for up to 20% of the Proposed Development export cable corridor length and up to 30% of inter-array cables and OSP/Offshore convertor substation platform interconnector cables. Boulder clearance may be required for up to 20% of offshore export cables length, inter-array cables and OSP/Offshore convertor substation platform interconnector cable ( Table 9.15   Open ▸ ). The maximum width of seabed preparation is greater than the disturbance associated with the cable installation itself to allow enough space to operate the tool (i.e. 15 m for cable burial, 25 m for boulder clearance and 25 m for sand wave clearance). Cable burial will therefore occur within the area previously disturbed via sand wave or boulder clearance resulting in localised repeat disturbance within a 15 m wide corridor, within the wider 25 m corridor disturbed during sand wave and boulder clearance.
64. A recent review commissioned by The Crown Estate (TCE) reviewed the effects of cable installation on subtidal sediments and habitats (RPS, 2019), drawing on monitoring reports from over 20 UK offshore wind farms. This review showed that sandy sediments recover quickly following cable installation, with trenches infilling quickly following cable installation and little or no evidence of disturbance in the years following cable installation. It also presented evidence that in some settings, remnant cable trenches in coarse and mixed sediments and muddy sediments were conspicuous for several years after installation. However, these shallow depressions were of limited depth (i.e. tens of cm) relative to the surrounding seabed, over a horizontal distance of several metres and therefore did not represent a large shift from the baseline environment (RPS, 2019).
65. As set out in Table 9.15   Open ▸ , the maximum design scenario assumes the removal of up to 14 UXO from the Proposed Development. These clearance activities would however occur within the footprint of other seabed clearance works (i.e. sand wave and boulder clearance), cable burial activities and/or foundation footprints and therefore will not lead to additional habitat disturbance. Any craters created during detonation are expected to backfill by natural processes, the speed of which would depend on the sediment transport regimes in the area.
66. Anchor footprints from cable installation vessels will also result in habitat disturbance. Typically, one anchor reposition per 500 m of cable may be required, with individual anchors associated with cable installation vessels having a footprint of approximately 100 m2. This area of seabed disturbance will depend on the precise vessel used and in some cases anchor placements may not be required at all (e.g. where the vessel uses dynamic positioning). The maximum design scenario accounts for up to 438,200 m2 of temporary disturbance from a 100 m2 anchor placed every 500 m during inter-array, OSP/Offshore convertor substation platform interconnector and offshore export cables installation.
67. Jack-up footprints associated with foundation installation will result in compression of seabed sediments beneath spud cans where these are placed on the seabed. These will infill over time, although may remain on the seabed for a number of years, as demonstrated by monitoring studies of UK offshore wind farms (BOWind, 2008; EGS, 2011). Monitoring at the Barrow offshore wind farm showed depressions were almost entirely infilled 12 months after construction (BOWind, 2008). Monitoring at Lynn and Inner Dowsing offshore wind farm also showed some infilling of the footprints, although the depressions (i.e. of the order of tens of centimetres) were still visible a couple of years post construction (EGS, 2011). In areas where mobile sands and coarse sediments are present such as in the majority of the Proposed Development fish and shellfish ecology study area (see volume 2, chapter 8), jack-up depressions are likely to be temporary features which will only persist for a period of months to a small number of years.
68. Activities resulting in the temporary subtidal habitat loss/disturbance will occur intermittently throughout the construction phase. The offshore construction phase which includes activities resulting in temporary habitat loss/disturbance will occur over a period of up to 96 months. Once construction in a local area (for example, a section of offshore export cable) has been completed, this area will not be disturbed further during the construction phase. This area will start to recover immediately following cessation of construction activities in the vicinity allowing mobile species, such as sandeel and other fish and shellfish species, to repopulate the areas of previous disturbance (see paragraph 78 et seq. for further discussion of recovery of species).
69. The impact is predicted to be of local spatial extent (i.e. limited to the Proposed Development fish and shellfish ecology study area), medium term duration (although only a small proportion of the total area will be affected at any one time with individual elements of construction having much shorter durations), intermittent and high reversibility. It is predicted that the impact will affect the receptor directly or indirectly, dependent on species’ life strategies. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

Marine species

70. In general, mobile fish species are able to avoid areas subject to temporary habitat disturbance (EMU, 2004). The most vulnerable species are likely to be shellfish which are much less mobile than fish. For example, egg bearing lobster are thought to be more restricted to an area based on a mark and recapture study in Norway which showed that 84% of berried female lobster remained within 500 m of their release site (Agnalt et al., 2007). Evidence from other stocks around the world are less clear, with limited movement recorded for some stocks and long distance migrations documented for other stocks (e.g. Campbell and Stasko,1985; Comeau and Savoie, 2002).
71. Indirect effects on fish and shellfish species also include loss of feeding habitat and prey items. For example, crabs and other crustaceans and small benthic fish species (as well as other benthic species; see volume 2, chapter 8) are considered important prey species for larger fish. However, since this impact is predicted to affect only a small proportion of seabed habitats in the Proposed Development fish and shellfish ecology study area at any one time, with similar habitats (and prey species) occurring throughout the Forth and Tay SMR and the wider Proposed Development northern North Sea fish and shellfish ecology study area, these effects are likely to be limited and highly reversible. Conversely, habitat disturbance during the construction phase will also expose benthic infaunal species from the sediment (see volume 2, chapter 8), potentially offering foraging opportunities to some fish and shellfish species (e.g. opportunistic scavenging species) immediately after completion of works. The implications of changes in fish and shellfish prey species are also discussed for higher trophic level receptors (i.e. marine mammals and birds) in volume 2, chapter 10 and chapter 11.
72. A number of commercially important shellfish species such as edible crab, lobster, Nephrops, scallop and velvet swimming crab are known to inhabit the Proposed Development fish and shellfish ecology study area. Habitat loss in this area will represent a relatively small temporary disturbance to these habitats (e.g. during cable laying and seabed preparation), with relatively rapid recovery of sediments (RPS, 2019), and following this, recovery of associated communities (see volume 2, chapter 8) including shellfish populations into these areas. The recoverability and rate of recovery of an area after large scale seabed disturbance (e.g. dredging or trawling activities) is linked to the substrate type (Newell et al., 1998; Desprez, 2000). Mud or sand habitats, similar to those found in the Proposed Development fish and shellfish ecology study area, have been shown to return to baseline species abundance after approximately one to two years (Newell et al., 1998; Desprez, 2000). Harder gravely and rocky substrate takes proportionally longer to re‑establish: up to ten years for boulder coastlines (Newell et al., 1998).
73. Larger crustacea (e.g. Nephrops, European lobster) are classed as equilibrium species (Newell et al., 1998) and are only capable of recolonising an area once the original substrate type has returned. The sensitivity of these fish and shellfish IEFs is therefore higher than for smaller benthic organisms which move in and colonise new substrate immediately after the effect. Therefore, although recovery of benthic assemblages may occur over relatively fast timescales (e.g. within one to two years; see volume 2, chapter 8), recovery of the equilibrium species may take up to ten years in some areas of coarse sediments (Phua et al., 2002).
74. Construction operations (including cable installation) within the Proposed Development fish and shellfish ecology study area may also impact on spawning and nursery habitats for Nephrops, as these areas overlap and have been mapped (i.e. broadscale mapping by Coull et al., 1998) as coinciding with the Proposed Development fish and shellfish ecology study area (volume 3, appendix 9.1). However, site-specific surveys showed that Nephrops were only recorded along the Proposed Development export cable corridor and therefore would only be affected by a relatively small proportion of the proposed construction operations. Further, larval settlement will also increase the rate of recovery in an area (Phua et al., 2002), with shellfish (Nephrops) spawning and nursery habitats in the vicinity of the Proposed Development fish and shellfish ecology study area (see volume 3, appendix 9.1) potentially increasing the rate of recovery into disturbed areas. A recent study undertaken during construction of the Westermost Rough Offshore Wind Farm located on the north-east coast of England, within a European lobster fishing ground, found that the size and abundance of lobster individuals increased following temporary closure or the area for construction of the wind farm. This study shows that the activities associated with construction of the wind farm, which included installation of wind turbines and cables, did not impact on resident lobster populations and instead allowed some respite from fishing activities for a short time period before reopening following construction (Roach et al., 2018).
75. Scallop are likely to be present within the Proposed Development fish and shellfish ecology study area and are targeted by commercial fisheries activities (see volume 2, chapter 12). Scallop are predominantly sessile organisms, however, they do have the ability to swim, which is ordinarily used as an escape response, although limited in distance (Marshall and Wilson, 2008). It has been documented the scallop have been able to move up to 30 m from a release site during a tagging study (Howell & Fraser, 1984). This response may allow improved resilience to temporary habitat loss/disturbance than other sessile organisms, by being able to avoid areas of disturbance and relocate to areas nearby. Scallop tend to occur in aggregations as their larval distribution is reliant on hydrographic features (Brand, 1991), therefore assuming scallop populations continue to spawn outside the boundary of the Proposed Development fish and shellfish ecology study area and within unimpacted areas of the Proposed Development, and suitable habitat for settlement remains, it is likely that scallop will continue to be recruited into the Proposed Development fish and shellfish ecology study area. Therefore, scallop will recover well from any disturbance due to short term habitat loss. This is supported by the MarLIN sensitivity assessment (Marshall and Wilson, 2008) which concluded scallops have a high recovery potential (i.e. recovery within months, with full recovery in a small number of years).
76. The fish species within the Proposed Development fish and shellfish ecology study area which are likely to be most sensitive to temporary habitat loss are those species which spawn on or near the seabed sediment (e.g. herring, sandeel and elasmobranchs, including spotted ray). Of the IEF fish species that spawn on or near the seabed, sandeel and herring are known to spawn at varying intensities within the vicinity of the Proposed Development fish and shellfish ecology study area (see volume 3, appendix 9.1). Therefore, seabed disturbance activities carried out during spawning periods may result in some mortality of eggs and reduced opportunity due to removal of suitable habitat. However, the area which will be disturbed is small given the abundance of similar substrate types and the extensive nature of fish spawning grounds across the Proposed Development northern North Sea fish and shellfish ecology study area.
77. Physical disturbance to sandeel habitats may also lead to direct effects on adult and juvenile sandeel (e.g. increased mortality), where individuals are not able to colonise viable sandy habitats in the immediate vicinity, or where habitats may be at carrying capacity (Wright et al., 2000). This is as identified by the FeAST tool as a pressure on sandeel ‘sub-surface abrasion/penetration’ which has noted that sandeel have high sensitivity to this impact (Wright et al., 2000). Sandeel may also be particularly vulnerable during their winter hibernation period when they bury themselves in the seabed substrates and are therefore less mobile. A large proportion of temporary habitat disturbance (60,342,400 m2) is related to construction activities within the Proposed Development export cable corridor. The majority of favourable and preferred sandeel habitat within the Proposed Development fish and shellfish ecology study area is located within the Proposed Development array area (as described in section 9.7). Therefore, a significant proportion of temporary habitat disturbance will take place within areas of less favourable habitat within the Proposed Development export cable corridor. The temporary subtidal habitat loss/disturbance in the Proposed Development array area alone equates to up to 53,632,300 m2. As a proportion of the Proposed Development array area, this accounts for up to 5.3%, which is a relatively small proportion in the context of available habitat in the Proposed Development array area and across the wider Firth and Tay SMR. Further, as noted above, only a small proportion of this maximum footprint of habitat loss/disturbance will be occurring at any one time during the construction phase, with recovery of sediments, and sandeel populations into them.
78. Recovery of sandeel populations would be expected following construction operations, with the rate of recovery dependent on the recovery of sediments to a condition suitable for sandeel recolonisation. Effects of offshore wind farm construction (Jensen et al., 2004) and operation (i.e. post-construction) (van Deurs et al., 2012) on sandeel populations have been examined through short term and long term monitoring studies at the Horns Rev offshore wind farm in the Baltic Sea, Denmark. These monitoring studies have shown that offshore wind farm construction and operation has not led to significant adverse effects on sandeel populations and that recovery of sandeel occurs quickly following construction operations.
79. The recovery potential of sandeel populations can also be inferred from a study by Jensen et al. (2010), which found sandeel populations mix within fishing grounds to distances of up to 28 km. This suggests that some recovery of adult populations is likely following construction operations, with adults recolonising suitable sandy substrates from adjacent un-impacted habitats. Recovery may also occur through larval recolonisation of suitable sandy sediments with sandeel larvae likely to be distributed throughout the Proposed Development fish and shellfish ecology study area during spring months following spawning in winter/spring (see Ellis et al., 2012; and volume 3, appendix 9.1).
80. A recent monitoring study conducted at the Beatrice Offshore Wind Farm completed a post construction sandeel survey where sandeel abundance were compared pre and post construction (BOWL, 2021a). The results showed that sandeel abundance either increased or remained at similar levels when comparing abundance from 2014 to 2020, with offshore construction commencing in April 2017. The study concluded that there was no evidence that the construction of Beatrice Offshore Wind Farm resulted in adverse impacts on the local sandeel population. This conclusion should be seen in the context of general increase in sandeel populations in the area surrounding the Beatrice Offshore Wind Farm (using ICES set Total Allowable Catch (TAC) as an indicator), and an increase in bycatch abundance from the sandeel dredging, which may indicate the Beatrice Offshore Wind Farm site was generally healthier in 2020 than it was in 2014 (BOWL, 2021a). This study builds on previous work conducted by Stenberg et al. (2011) which concluded that the construction of the Horns Rev 1 Offshore Wind Farm posed neither a threat nor direct benefit to sandeel over a seven-year period.
81. As described in paragraph 68, temporary habitat loss during the construction phase (96 months), will not occur simultaneously across the entire Proposed Development array area, rather only a small proportion of the maximum habitat loss/disturbance footprint will occur at a particular location at any one time. Once construction/infrastructure installation works are complete in a specific area, recovery of sediments and associated communities will begin. Drawing on information from the monitoring studies above, it is highly likely that the displaced individuals will repopulate these previously disturbed areas, with recovery occurring throughout the construction phase rather than once the entire construction phase is completed.
82. As effects on sandeel (and other prey species) are predicted to be limited in extent (particularly in the context of available habitats in the Proposed Development northern North Sea fish and shellfish ecology study area), temporary and reversible, with recovery of sandeel populations occurring post construction, species reliant on sandeel and other small prey species (e.g. sea trout and cod) would similarly not be expected to be significantly affected. The implications of changes in fish and shellfish prey species are also discussed for higher trophic level receptors (i.e. marine mammals and birds) in volume 2, chapter 10 and volume 2, chapter 11.
83. Herring spawning has been demonstrated to take place within the Proposed Development fish and shellfish ecology study area at a low intensity, with higher intensity spawning grounds being present to the north of the Proposed Development fish and shellfish ecology study area (see volume 3, appendix 9.1). Favourable habitat (gravel and sandy gravel) for spawning is present in patches within the Proposed Development fish and shellfish ecology study area, however, the area affected by temporary habitat loss (i.e. within the Proposed Development array area only) is dominated by sediments which are not suitable for herring spawning and therefore the area of herring spawning grounds affected by this impact is expected to be very limited, in the context of available favourable sediments habitat outside the Proposed Development fish and shellfish ecology study area and across the wider Proposed Development northern North Sea fish and shellfish ecology study area.
84. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
85. European lobster and Nephrops are deemed to be of high vulnerability, medium to high recoverability and of regional importance. The sensitivity of these fish and shellfish IEFs is therefore considered to be medium.
86. Herring are deemed to be of high vulnerability, medium recoverability and of regional importance. However, the sensitivity of herring to this impact is considered to be low, due to the limited suitable spawning sediments overlapping with the Proposed Development fish and shellfish ecology study area and the core herring spawning ground being located well outside the Proposed Development fish and shellfish ecology study area.
87. Sandeel are deemed to be of high vulnerability, high recoverability and of national importance. The sensitivity of sandeel is therefore considered to be medium.

Diadromous Species

88. Diadromous fish species are highly mobile and therefore are generally able to avoid areas subject to temporary habitat loss. Diadromous species that are likely to interact with the Proposed Development fish and shellfish ecology study area are only likely to do so by passing through the area during migrations to and from rivers located on the east coast of Scotland, such as to rivers with designated sites, with diadromous fish species listed as qualifying features (see Table 9.12   Open ▸ and volume 3, appendix 9.1). The habitats within the Proposed Development fish and shellfish ecology study area are not expected to be particularly important for diadromous fish species and therefore habitat loss during the construction phase of the Proposed Development fish and shellfish ecology study area is unlikely to cause any direct impact to diadromous fish species and would not affect migration to and from rivers.
89. Indirect impacts on diadromous fish species may occur due to impacts on prey species, for example larger fish species for sea lamprey and sandeel for sea trout. As outlined for marine species above, the majority of large fish species would be able to avoid habitat loss effects due to their greater mobility but would recover into the areas affected following cessation of construction. Sandeel (and other less mobile prey species) would be affected by temporary habitat loss, although recovery of this species is expected to occur quickly as the sediments recover following installation of infrastructure and adults recolonise and also via larval recolonisation of the sandy sediments, which dominate the Proposed Development fish and shellfish ecology study area and are known to recover quickly following cable installation (RPS, 2019). Diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the Effect

Marine Species

90. Overall, the magnitude of the impact is deemed to be low and the sensitivity of most fish IEFs (including herring) is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
91. For sandeel, the magnitude of the impact is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance which is not significant in EIA terms. Although, the total figure for the area of subtidal habitat loss/disturbance is high, it should be viewed with the following context:

• a large proportion of habitat loss occurs within the Proposed Development export cable corridor, where habitat is less favourable/unsuitable for sandeel; and
• the total habitat loss/disturbance will not occur simultaneously, rather it would be spread across the site over the entire 96 months construction phase, allowing recovery into disturbed areas to begin as soon as construction activity has ceased.
  92. For Nephrops and European lobster, the magnitude of the impact is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance which is not significant in EIA terms. It should be noted that there is some conservatism in this conclusion, specifically:
• Nephrops are distributed across only part of the Proposed Development export cable corridor, with more extensive habitats outside the Proposed Development fish and shellfish ecology study area and therefore would not be affected by the majority of the construction operations, particularly those occurring within the Proposed Development array area which are not suitable habitats for Nephrops; and
• similarly, lobster are likely to be targeted in nearshore areas including sections of the offshore export cable route. There is some creeling activity (which targets lobster and crab species) (see volume 3, appendix 12.1) within the Proposed Development array area, however lobster are typically associated with coarser sediments than those found within the Proposed Development fish and shellfish ecology study area and, it is likely that the creeling effort is focused on crab species rather than lobster.

Diadromous Species

93. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

94. No additional fish and shellfish ecology mitigation is considered necessary as recovery of sediments and associated fish and shellfish IEFs will occur naturally without any need for further interventions and the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Operation and Maintenance Phase

Magnitude of Impact

95. Operation and maintenance activities within Proposed Development fish and shellfish ecology study area may lead to temporary subtidal habitat loss/disturbance. The maximum design scenario is for up to 989,000 m2 of temporary habitat loss/disturbance during the operation and maintenance phase ( Table 9.15   Open ▸ ). This equates to 0.08% of the Proposed Development and therefore this represents a very small proportion of the Proposed Development fish and shellfish ecology study area. It should also be noted that only a small proportion of the total habitat loss/disturbance is likely to be occurring at any one time over the 35-year operation phase of the Proposed Development.
96. Temporary habitat loss will occur as a result of the use of jack-up vessels during any component replacement activities and during any inter-array, OSP/Offshore convertor substation platform interconnector and offshore export cable repair activities. Impacts of jack-up vessel activities will be similar to those identified for the construction phase above and will be restricted to the immediate area around the wind turbine foundation or cable repair site, where the spud cans are placed on the seabed, with recovery occurring following removal of spud cans. Inter-array and offshore export cable repair or reburial activities will also affect habitats in the immediate vicinity of these operations, with effects on seabed habitats also expected to be similar to the construction phase. The spatial extent of this impact is very small in relation to the Proposed Development fish and shellfish ecology study area, although there is the potential for repeat disturbance to the habitats because of these activities (e.g. placement of spud cans on or in close proximity to where these were placed during construction; remedial burial of a length of cable installed during the construction phase, affecting the same area of seabed). Activities resulting in the temporary subtidal habitat loss/disturbance will occur intermittently throughout the 35-year operation and maintenance phase.
97. The impact is predicted to be of local spatial extent, short term duration (individual maintenance operations would occur over the period of days to weeks), intermittent and high reversibility. It is predicted that the impact will affect the receptor directly or indirectly, dependent on species’ life strategies. The magnitude is therefore considered to be negligible.

Sensitivity of the Receptor

98. The sensitivity of the fish and shellfish IEFs, for both marine and diadromous species, can be found in the construction phase assessment (see paragraph 70 et seq.), ranging from negligible to medium sensitivity.

Significance of the Effect

Marine Species

99. Overall, the magnitude of the impact is deemed to be negligible and the sensitivity of most fish IEFs (including herring) is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
100. For sandeel, the magnitude of the impact is deemed to be negligible and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
101. For Lobster and Nephrops, the magnitude of the impact is deemed to be negligible and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

102. Overall, the magnitude of the impact is deemed to be negligible and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

103. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning Phase

Magnitude of Impact

104. Decommissioning activities within the Proposed Development fish and shellfish ecology study area may lead to temporary subtidal habitat loss/disturbance. The decommissioning activities includes jack-up vessels during foundation removal, removal of inter-array, interconnector and offshore export cables, and associated anchor placements during said cables removal. The maximum design scenario is for up to 34,571,200 m2 of temporary habitat loss/disturbance is during the decommissioning phase ( Table 9.15   Open ▸ ). This equates to 2.9% of the Proposed Development, with only a small proportion of this total area affected at any one time during the decommissioning phase. For the purposes of this assessment, the impacts of decommissioning are predicted to be similar to those for the construction phase (see paragraph 62 et seq.), although expected to be considerably less as seabed clearance may not be required.
105. The impact is predicted to be of local spatial extent (within the boundaries of the Proposed Development fish and shellfish ecology study area), medium term duration (although only a small proportion of the total area will be affected at any one time with individual elements of decommissioning having much shorter durations), intermittent and high reversibility. It is predicted that the impact will affect the receptor directly or indirectly, dependent on species’ life strategies. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

106. The sensitivity of the fish and shellfish IEFs, for both marine and diadromous species, can be found in the construction phase assessment (see paragraph 70 et seq.) ranging from negligible to medium sensitivity.

Significance of the Effect

Marine Species

107. Overall, the magnitude of the impact is deemed to be low and the sensitivity of most fish IEFs (including herring) is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
108. For sandeel, the magnitude of the impact is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance which is not significant in EIA terms.
109. For Nephrops and European lobster, the magnitude of the impact is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance which is not significant in EIA terms. It should be noted that there is some conservatism in this conclusion, specifically:

Diadromous Species

110. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptors is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

111. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Increased suspended sediment concentrations and associated sediment deposition

112. Increases in SSC and associated sediment deposition are predicted to occur during the construction and decommissioning phases as a result of seabed preparation, the installation/removal of foundations and installation/removal of inter-array, interconnector and offshore export cables. Increases in suspended sediments and associated sediment deposition are also predicted to occur during the operation and maintenance phase due to inter-array and offshore export cable repair and reburial events. Volume 3, appendix 7.1 provides a full description of the physical processes baseline characterisation, including numerical modelling used to inform the predictions made with respect to increases in suspended sediment and subsequent deposition.

Construction Phase

Magnitude of Impact

113. The installation of infrastructure within the Proposed Development fish and shellfish ecology study area may lead to increases SSC and associated sediment deposition. Full details of the modelling undertaken to inform this assessment is presented in volume 3, appendix 7.1, including the individual scenarios considered and assumptions within these and full modelling outputs for suspended sediments and associated sediment deposition. For the purposes of this assessment, the following activities have been considered:

• seabed feature clearance prior to cable installation;
• drilling for foundation installation; and
• inter-array, OSP/Offshore convertor substation platform interconnector, and offshore export cable installation.
  114. Sand wave clearance for cable installation would involve disturbance of seabed material within a corridor of up to 25 m width for the 20% the Proposed Development offshore export cables, where it is necessary. Modelling of suspended sediments to quantify the potential increases in SSC and sedimentation during sand wave clearance simulated the use of a suction hopper dredger to remove material from the crest of sand waves and deposit material in the adjacent trough. Modelling associated with the site preparation showed a large variation. SSC reaches its peak in the disposal phase with concentrations reaching 2,500 mg/l at the release site, but the plume is at its most extensive when the deposited material is redistributed on the successive tides, under these circumstance concentrations of 100 mg/l to 250 mg/l have been modelled (see volume 3 appendix 7.1 for further details on modelling assumptions for SSC). The average SSC during the course of the clearance activities is presented in volume 3, appendix 7.1, with values less than 100 mg/l with a plume width of 10 km. Sedimentation of deposited material is focussed within 100 m of the site of release with a maximum depth 0.5 m – 0.75 m (this is considered within temporary habitat loss, see paragraph 62 et seq. and Table 9.15   Open ▸ ) whilst the finer sediment fractions are distributed in the vicinity at much lesser depths circa 5 mm – 10 mm within a range of hundreds of meters to a small number of kilometres. Sedimentation one day following cessation of operation is similar to during operation with a small extension to the area over which sedimentation has occurred but with no increase in maximum sedimentation depth (physical processes modelling detailed in volume 3, appendix 7.1). The dispersion of the released material would continue on successive tides and be incorporated into the baseline sediment transport regime, returning to background levels within a few tides.
  115. The maximum design scenario for the inter-array cable sand wave clearance also accounts for up to a 25 m wide corridor. The resulting SSC showed similar characteristics to the offshore export cables clearance. At the Proposed Development array area, the greatest area of increased SSC was also shown to be associated with re-mobilisation of the deposited material on subsequent tides. In this scenario, the plume was found to extend 10 km from the site, with peak concentrations of 100 mg/l – 250 mg/l and average levels are less than 100 mg/l. Again, SSCs were predicted to reach their peak in the dumping phase with concentrations reaching 2,500 mg/l at the release site. The average sedimentation depth is typically half that of the offshore export cable works, with maximum sedimentation of 100 –m - 300 mm, which is only reached in very small areas along the Proposed Development export cable corridor, and almost all within the Proposed Development fish and shellfish ecology study area. The sedimentation one day following the cessation of the clearance operation shows deposited material at the site of release with depth 0.2 m – 0.4 m (this is considered within temporary habitat loss, see paragraph 62 et seq. and Table 9.15   Open ▸ ) whilst in the locality, lower depths, typically less than 5 mm, are present at 50 m distance from the release. The dispersion of the released material would continue on successive tides and be incorporated into the baseline sediment transport regime, returning to background levels within a few tides.
  116. The maximum design scenario for foundation installation assumes all wind turbine and OSP/Offshore convertor substation platform foundations will be installed by drilling 5.5 m diameter piles for jacket foundations ( Table 9.15   Open ▸ ). Drilling was modelled for three wind turbines at different locations in the Proposed Development array area. The locations represent the dominant physical environmental conditions experienced in the Proposed Development array area. Modelling of SSCs associated with the foundation installation showed the plume related directly to the sediment releases was less than 5 mg/l and this drops to lower levels within a very short distance, typically less than 500 m. Furthermore, these sediment plumes are predicted to be temporary, returning to background levels within a few tides. The maximum sedimentation depth is typically 0.05 mm to 0.1 mm during pile installation, with that maximum dropping to 0.0005 mm – 0.001 mm one day following cessation of operations. These demonstrate the dispersive nature of the site, dispersing material the full extent of the tidal excursion (12 km), and even using a very small contour interval this settlement would be imperceptible from the background sediment transport activity with plotted sediment depths less than typical grain diameters.
  117. The maximum design scenario for the installation of inter-array and OSP/Offshore convertor substation platform interconnector cables assumes installation of all cables through jet trenching, with assumptions (e.g. trench width and depth) summarised in Table 9.15   Open ▸ . Modelling was undertaken for installation of inter-array and OSP/Offshore convertor substation platform interconnector cables along a number of paths which connect groups of wind turbines to OSP/Offshore convertor substation platforms or connect two OSP/Offshore convertor substation platforms to each other. Each route would be undertaken as a separate operation and thus a single example has been selected to quantify the potential suspended sediment levels during the installation. The inter-array cabling was modelled along a route with a trench 2 m wide and 3 m in depth. The modelling outputs for SSCs associated with the installation of cabling showed a very wavy plume extending from trenching route, the majority of which sits within the Proposed Development array area. It is clear that the sediment is re-suspended and dispersed on subsequent tides as the plume envelope is most extensive towards the start of the route to the south-east of the site with peak values of 100 mg/l extending hundreds of meters to a small number of kilometres. The volume of material mobilised is relatively large, and elevated tidal currents disperse the material giving rise to concentrations of up to 500 mg/l. The sedimentation is greatest at the location of the trenching and may be up to 30 mm in depth however within close proximity, circa 100 m, the depths reduce significantly.
  118. The modelling for offshore export cables also took a precautionary approach, assuming that cable installation would involve disturbance of seabed material up to 2 m wide and up to 3 m deep. Modelling outputs indicated average SSC along the route ranged between 50 mg/l and 500 mg/l. Average sedimentation peaks at 0.5 mm - 1.0 mm during offshore export cable installation and one day after cessation of operations this maximum increased to 10 mm - 30 mm, however this only accounts for a very small area with most of the impacted area displaying deposition depths considerably reduced at distance from the cable trench, returning to background levels within a few tides.
  119. The impact is predicted to be of local spatial extent (i.e. largely within the Proposed Development fish and shellfish ecology study area boundaries), short term duration, intermittent during the construction phase and high reversibility. It is predicted that the impact will affect the receptors directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

Marine Species

120. In terms of SSC, adult fish species are more mobile than many of the other fish and shellfish IEFs, and therefore may show avoidance behaviour within areas affected by increased SSC (EMU, 2004), making them less susceptible to physiological effects of this impact. Juvenile fish are more likely to be affected by habitat disturbances such as increased SSC than adult fish. This is due to the decreased mobility of juvenile fish and these animals are therefore less able to avoid impacts. Juvenile fish are likely to occur throughout the Proposed Development fish and shellfish ecology study area, with some species using offshore areas as nursery habitats while inshore areas are more important as nurseries for other species (see section 9.7 and volume 3 appendix 9.1). Due to the temporary increases in SSC associated with winter storm events and the occurrence of juveniles in inshore areas (where SSCs are typically higher), it can be expected that most fish juveniles expected to occur in the Proposed Development fish and shellfish ecology study area (see Table 9.11   Open ▸ for species with nursery grounds overlapping the Proposed Development fish and shellfish ecology study area) will be largely unaffected by the low level temporary increases in SSC, as the concentrations are likely to be within the range of natural variability (generally <5 mg/l but can increase to over 100 mg/l during storm events/increased wave heights) for these species and will reduce to background concentrations within a very short period (approximately two tidal cycles).
121. A study by Appleby and Scarratt (1989) found development of eggs and larvae have the potential to be affected by suspended sediments at concentrations of thousands of mg/l. Modelling undertaken of SSC associated with the Proposed Development fish and shellfish ecology study area construction phase identified peak maximum concentrations of 2,500 mg/l predicted in the dumping phase of sand wave clearance activities at the release site. These concentrations of SSC may affect the development of eggs and larvae, however, these concentrations are only expected to be present in the immediate vicinity of the release site with dispersion of the released material continuing on successive tides. Average increases in SSC associated with sand wave clearance activities are predicted to be of the order of less than 100 mg/l. These levels are unlikely to affect the development of eggs and larvae.
122. Many shellfish species, such as edible crab, have a high tolerance to SSC and are reported to be insensitive to increases in turbidity; however, they are likely to avoid areas of increased SSC as they rely on visual acuity during predation (Neal and Wilson, 2008). Berried crustaceans (e.g. European lobster and Nephrops) are likely to be more vulnerable to increased SSC as the eggs carried by these species require regular aeration. Increased SSC within the Proposed Development fish and shellfish ecology study area (potential habitat for egg bearing and spawning Nephrops, particularly along the Proposed Development export cable corridor) will only affect a small area at any one time and will be temporary in nature, with sediments settling to the seabed quickly following disturbance (see assessment of magnitude above). Nephrops are not considered to be sensitive to increases in SSC or subsequent sediment deposition, since this is a burrowing species with the ability to excavate any sediment deposited within their burrows (Sabatini and Hill, 2008).
123. The species likely to be affected by sediment deposition are those which either feed or spawn on or near the seabed. Demersal spawners within the Proposed Development fish and shellfish ecology study area include sandeel. Spawning areas for sandeel occur within the Proposed Development fish and shellfish ecology study area, however sandeel eggs are likely to be tolerant to some level of sediment deposition due to the nature of re-suspension and deposition within their natural high energy environment. Therefore, effects on sandeel spawning populations are predicted to be limited. Sandeel populations are also sensitive to sediment type within their habitat, preferring coarse to medium sands and showing reduced selection or avoidance of gravel and fine sediments (Holland et al., 2005). This is as identified by the FeAST tool as the pressure ‘siltation changes’ (low) which has identified that sandeel have medium sensitivity to this impact (Wright et al., 2000). Therefore, any increase in the fine sediment fraction of their habitat may cause avoidance behaviour until such time that currents remove fine sediments from the seabed, although modelled sediment deposition levels are expected to be highly localised and at very low levels (less than 10 mm).
124. With respect to the effects of sediment deposition on herring spawning activity, it has been shown that herring eggs may be tolerant of very high levels of SSC (Mesieh et al., 1981; Kiorbe et al., 1981). Detrimental effects may be seen if smothering occurs and the deposited sediment is not removed by the currents (Birklund and Wijsmam, 2005), however this would be expected to occur quickly (i.e. within a couple of tidal cycles) with such a small amount of sediment deposition being forecast. Furthermore, the relatively limited amount of suitable sediments for herring spawning and the mapping of the core herring spawning habitats well outside the Proposed Development fish and shellfish ecology study area would also limit the potential for effects on herring spawning.
125. Based on the increase in sensitivity of herring eggs to the smothering effects of increased sediment deposition, herring is deemed to be of medium vulnerability, high recoverability and of regional importance, and therefore the sensitivity of this receptor is considered to be medium.
126. All other fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of these IEFs is therefore considered to be low.

Diadromous Species

127. Diadromous fish species known to occur in the area are also expected to have some tolerance to naturally high SSC, given their migration routes typically pass through estuarine habitats which have background SSC which are considerably higher than those expected in the offshore areas of the Proposed Development northern North Sea fish and shellfish ecology study area. As it is predicted that construction activities associated with the Proposed Development will produce temporary and short lived increases in SSC, with levels well below those experienced in estuarine environments, it would be expected that any diadromous species should only be temporarily affected (if they are affected at all). Any adverse effects on these species are likely to be short term behavioural effects (i.e. avoidance) and are not expected to create a barrier to migration to rivers or estuaries used by these species in the Proposed Development northern North Sea fish and shellfish ecology study area.
128. Diadromous fish species IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptors is therefore, considered to be low.

Significance of the Effect

Marine Species

129. Overall, the magnitude of the impact is deemed to be low and the sensitivity for most fish and shellfish IEFs is considered to be low to medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
130. For herring, the magnitude of the impact is deemed to be low and the sensitivity is considered medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
131. For Nephrops and lobster, the magnitude of the impact is deemed to be low and the sensitivity is considered low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

132. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptors is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

133. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Operation and Maintenance Phase

Magnitude of Impact

134. Operation and maintenance activities within the Proposed Development fish and shellfish ecology study area will lead to an increase in SSCs and associated sediment deposition, including repair and reburial of inter-array, OSP/Offshore convertor substation platform interconnector and offshore export cables using similar methods as those for cable installation activities (e.g. jet trenching), undertaken at intervals during the 35-year operation and maintenance phase (see Table 9.15   Open ▸ ).
135. Any suspended sediments and associated deposition will be of the same magnitude as, or lower than, the construction phase. Volume 2, chapter 7 predicts the magnitude of SSC to be negligible and therefore, for the purposes of this assessment, the impacts of the operation and maintenance activities (i.e. cable repair and reburial) are predicted to be no greater than those for construction.
136. The impact is predicted to be of local spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptors directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

137. The sensitivity of the fish and shellfish IEFs, for both marine and diadromous species, can be found in the construction phase assessment (see paragraph 120).

Significance of the Effect

Marine Species

138. Overall, the magnitude of the impact is deemed to be low and the sensitivity for most fish and shellfish IEFs is considered to be low to medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
139. For herring, the magnitude of the impact is deemed to be low and the sensitivity is considered medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
140. For Nephrops and lobster, the magnitude of the impact is deemed to be low and the sensitivity is considered low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

141. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

142. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning Phase

Magnitude of Impact

143. Decommissioning of the infrastructure within the Proposed Development fish and shellfish ecology study area will lead to increases in SSCs and associated sediment deposition. The maximum design scenario is represented by the cutting and removal of piled substructures at an agreed depth below the level of the seabed for partial removal, removal of suction caisson foundations, removal of inter-array, OSP/Offshore convertor substation platform interconnector and offshore export cables using jet trenching which mobilises material from a depth of up to 3 m deep in a trench of up to 2 m wide.
144. Decommissioning of foundations is predicted to result in increases in suspended sediments and associated deposition that are no greater than those produced during construction, and likely to be smaller as seabed clearance is less likely to be required. For the purpose of this assessment, as described in volume 2, chapter 7, the impacts of decommissioning activities are predicted to be no greater than those for construction (see paragraph 113 et seq.).
145. The impact is predicted to be of local spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

146. The sensitivity of the fish and shellfish IEFs, for both marine and diadromous species, can be found in the construction phase assessment (see paragraph 120 et seq.).

Significance of the effect

Marine Species

147. Overall, the magnitude of the impact is deemed to be low and the sensitivity for most fish and shellfish IEFs is considered to be low to medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
148. For herring, the magnitude of the impact is deemed to be low and the sensitivity is considered medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
149. For Nephrops and lobster, the magnitude of the impact is deemed to be low and the sensitivity is considered low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

150. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

151. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Injury and/or disturbance to fish and shellfish from underwater noise and vibration

Construction Phase

Magnitude of Impact

152. The installation of foundations within the Proposed Development fish and shellfish ecology study area may lead to injury and/or disturbance to fish and shellfish species due to underwater noise during pile driving. The maximum design scenario, as outlined in Table 9.15   Open ▸ , considers the greatest effect from underwater noise on fish and shellfish IEFs, considering both the greatest hammer energy. This scenario is represented by the installation of up to 179 piled jacket foundations (1,432 piles) for wind turbines, and up to ten jacket foundations (256 piles) for OSP/Offshore convertor substation platforms, with each pile installed via impact/percussive piling. Two scenarios were modelled with respect to hammer energy: an average maximum hammer energy of 3,000 kJ and an absolute maximum hammer energy of up to 4,000 kJ.
153. For wind turbines, piling was assumed to take place over a period of on average nine hours per pile (maximum duration of up to ten hours per pile) with up to five piles installed in each 24-hour period. OSP/Offshore convertor substation platform foundations will take place over a period of on average seven hours per pile (maximum duration of up to eight hours per pile) with up to three piles installed in each 24-hour period. A maximum duration of 16,368 hours of piling activity, over a maximum 372-day period, may take place during the construction phase, based on the maximum duration of the piling phase.
154. UXO clearance (including detonation) also has the capability to cause injury and/or disturbance to fish and shellfish IEFs. Clearance will be completed prior to the construction phase (pre-construction). Until detailed pre-construction surveys are completed within the Proposed Development fish and shellfish ecology study area, the precise number of potential UXO which will need to be cleared is unknown. Drawing on the experience of UXO at other North Sea sites, the maximum number of UXO that may require clearance is up to 14 for the Proposed Development. The maximum design scenario assumes that each of these will be detonated using low order processes, with the assumption that one high order detonation may occur (see Table 9.15   Open ▸ ). Many of these may be left in situ and microsited around. Detonation of UXO would represent a short term (i.e. seconds) increase in underwater noise (i.e. sound pressure levels and particle motion) which will be elevated to levels which may result in injury or behavioural effects on fish and shellfish species (discussed further in paragraph 159 et seq.).
155. To understand the magnitude of noise emissions from piling and UXO clearance during construction activity, underwater noise modelling has been undertaken considering the key parameters summarised above. Full details of the modelling undertaken are presented in volume 3, appendix 10.1.
156. Piling activities were modelled for jacket foundations at six locations within the Proposed Development fish and shellfish ecology study area array area taking into account the varying bathymetry and sediment type across the model areas (see volume 3, appendix 10.1). Underwater noise modelling included the use of ‘soft start’ mitigation to reduce the potential for injury effects (as set out in Table 9.20   Open ▸ ). The implications of the modelling for fish and shellfish injury and behaviour are outlined in the following sensitivity section.
157. All other noise sources including cable installation and foundation drilling are non-percussive and will result in much lower noise levels and therefore much smaller injury ranges (in most cases no injury is predicted) than those predicted for piling operations. For further information on other noise sources see volume 3, appendix 10.1.
158. The impact is predicted to be of regional spatial extent, medium term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

159. The following sections apply to both marine fish and shellfish species, and diadromous fish species, with a summary for each of these receptor groups in paragraphs 185 to 196.
160. Underwater noise can potentially have an adverse impact on fish species ranging from physical injury/mortality to behavioural effects. Recent peer reviewed guidelines have been published by the Acoustical Society of America (ASA) and provide directions and recommendations for setting criteria (including injury and behavioural criteria) for fish. The Sound Exposure Guidelines for Fishes and Sea Turtles (Popper et al., 2014) are considered to be most relevant and best available guidelines for impacts of underwater noise on fish species (see volume 3, appendix 10.1). The Popper et al. (2014) guidelines broadly group fish into the following categories according to the presence or absence of a swim bladder and on the potential for that swim bladder to improve the hearing sensitivity and range of hearing (Popper et al., 2014):

• Group 1: Fishes lacking swim bladders (e.g. elasmobranchs and flatfish). These species are only sensitive to particle motion, not sound pressure and show sensitivity to only a narrow band of frequencies;
• Group 2: Fishes with a swim bladder but the swim bladder does not play a role in hearing (e.g. salmonids and some Scombridae). These species are considered to be more sensitive to particle motion than sound pressure and show sensitivity to only a narrow band of frequencies;
• Group 3: Fishes with swim bladders that are close, but not connected, to the ear (e.g. gadoids and eels). These fishes are sensitive to both particle motion and sound pressure and show a more extended frequency range than Groups 1 and 2, extending to about 500 Hz; and
• Group 4: Fishes that have special structures mechanically linking the swim bladder to the ear (e.g. clupeids such as herring, sprat and shads). These fishes are sensitive primarily to sound pressure, although they also detect particle motion. These species have a wider frequency range, extending to several kHz and generally show higher sensitivity to sound pressure than fishes in Groups 1, 2 and 3.
  161. Relatively few studies have been conducted on impacts of underwater noise on invertebrates, including crustacean species, and little is known about the effects of anthropogenic underwater noise upon them (Hawkins and Popper, 2016; Morley et al., 2013; Williams et al., 2015). There are therefore no injury criteria that have been developed for shellfish, however, these are expected to be less sensitive than fish species and therefore injury ranges of fish could be considered to be conservative estimates for shellfish species (risk of behavioural effects are discussed further below for shellfish).
  162. An assessment of the potential for injury/mortality and behavioural effects to be experienced by fish and shellfish IEFs with reference to the sensitivity criteria described above is presented in turn below.

Injury

163. Table 9.21   Open ▸ summarises the fish injury criteria recommended for pile driving based on the Popper et al. (2014) guidelines, noting that dual criteria are adopted in these guidelines to account for the uncertainties associated with effects of underwater noise on fish.

Table 9.21: Criteria for Onset of Injury to Fish due to Impulsive Piling (Popper et al., 2014)

a Relative risk (high, moderate, low) is given for animals at three distances from the source defined in relative terms as near field (N; i.e. 10s of metres), intermediate (I; i.e. 100s of metres), and far field (F; i.e. 1000s of metres); Popper et al. (2014).

164. The full results of the underwater noise modelling are presented in volume 3, appendix 10.1. For the purpose of this assessment, a conversion factor range of 0.5 to 4% was applied as this represents an adequately conservative range for which energy from piling is transferred into sound energy. It should be noted that sensitivity analysis was undertaken on other, more conservative conversion factors, which is presented in volume 3, appendix 10.1. In order to inform this assessment, Table 9.22   Open ▸ and Table 9.23   Open ▸ display the predicted injury ranges associated with the installation of one 5.5 m diameter pile, for peak sound pressure levels (SPLpk) and cumulative sound exposure level (SELcum) respectively. This modelled scenario resulted in the greatest predicted injury ranges and therefore forms the focus of the assessment for injury.
165. For peak pressure noise levels when piling energy is at its maximum (i.e. 4,000 kJ), mortality and recoverable injury to fish may occur within approximately 138 m – 228 m of the piling activity (lower estimate for Group 1 fish species, higher estimate for Group 4 species). The potential for mortality or mortal injury to fish eggs would also occur at distances of up to 228 m ( Table 9.22   Open ▸ ), with a low to moderate risk of recoverable injury to eggs and larvae within the range of hundreds of metres (see Table 9.21   Open ▸ for qualitative criteria). It should be noted that these ranges are the maximum ranges for the maximum hammer energy, and it is unlikely that injury will occur in this range due to the implementation of soft starts during piling operations, which will allow fish to move away from the areas of highest noise levels, before they reach a level that would cause an injury. The initial injury ranges for soft start initiation will be considerably smaller than those maximum ranges presented in Table 9.22   Open ▸ (i.e. of the order of tens of metres, depending on the fish species considered).
166. For cumulative SEL, injury ranges were calculated for piling activities undertaken for the maximum energy scenario and for a realistic hammer energy scenario (i.e. average maximum; Table 9.23   Open ▸ ). These ranges indicate that with the implementation of soft start initiation, the mortality and recoverable injury ranges are considerably smaller than those predicted for SPLpk (i.e. mortality thresholds were not exceeded and recoverable injury to maximum ranges of 67 m; see Table 9.23   Open ▸ ). This table also presents ranges of effect for Temporary Threshold Shift (TTS) for all fish groups. As outlined above, TTS is a temporary reduction in hearing sensitivity caused by exposure to intense sound. Normal hearing ability returns following cessation of the noise causing TTS, though the recovery period is variable, during which fish may have decreased fitness due to a reduced ability to communicate, detect predators or prey, and/or assess their environment. Table 9.24   Open ▸ presents the ranges at which TTS in fish may occur as a result of piling for one 5.5 m pile, with TTS predicted to occur to maximum ranges of 4,161 m from piling operations (smaller ranges for basking shark and the realistic maximum hammer energy).
167. The injury ranges presented indicate that injury may occur out to ranges of tens to a few hundred metres, based on the maximum design scenario. However, in reality, the risk of fish injury will be considerably lower due to the hammer energies being lower than the absolute maximum modelled, as demonstrated by the lower injury ranges associated with initiation and soft starts in Table 9.22   Open ▸ . The expected fleeing behaviour of fish from the area affected when exposed to high levels of noise and the soft start procedure, which will be employed for all piling (see Table 9.20   Open ▸ ), mean that it is likely that fish will have sufficient time to vacate the areas where injury may occur prior to noise levels reaching that level.

Table 9.22: Summary of Peak Pressure Injury Ranges for Fish due to Phase of Impact Piling resulting in Maximum Peak Sound Pressure Level, for both Wind Turbine Foundations and OSP/Offshore Convertor Substation Platform Foundations Based on the Peak Pressure Metric

Table 9.23: Injury Ranges for Fish due to Impact Pile Driving for the “Realistic” and “Maximum” Pile Driving for Wind Turbine Jacket Foundations, and for the Piling of the OSP/Offshore Convertor Substation Platform Jackets Based on the Cumulative SEL Metric (N/E Denotes where Thresholds are not Exceeded)

168. Noise modelling was also undertaken for the concurrent piling of wind turbine foundations or wind turbine and OSP/Offshore convertor platform foundations. As outlined in volume 3, appendix 10.1, mortality and recoverable injury ranges were unchanged for the concurrent piling scenario and therefore TTS ranges only are presented in Table 9.24   Open ▸ . This indicates that for concurrent piling, TTS ranges may be increased to up to 7.1 km from the piling location and 5.6 km for realistic hammer energy.

Table 9.24: TTS Injury Ranges for Fish due to Impact Pile Driving at Two Locations Concurrently, for the “Realistic” and “Maximum” Pile Driving for Wind Turbine Jacket Foundations Based on the Cumulative SEL Metric

169. Underwater noise modelling has also been completed for underwater noise associated with UXO clearance/detonation. Modelling was undertaken for a range of orders of detonation, from a realistic worse case high order detonation to low order detonations (e.g. deflagration and clearance shots) to be used as mitigation to minimise noise levels. Table 9.25   Open ▸ details the injury ranges for fish of all groups in relation to various orders of detonation. The method of low order has been committed to (see Table 9.20   Open ▸ ) and as such will be the dominant method of UXO clearance, although higher order detonations may also occur if low order is not successful or unintentionally as part of the low order process.

Table 9.25: Injury Ranges for all Fish Groups Relating to Varying Orders of Detonation

170. Of the key shellfish species of the Proposed Development fish and shellfish ecology study area, decapod crustaceans (e.g. European lobster and crab) are believed to be physiologically resilient to noise as they lack gas filled spaces within their bodies (Popper et al., 2001). To date no lethal effects of underwater noise have been described for edible crab, European lobster or Nephrops, however a number of sub-lethal physiological effects have been reported among Nephrops and related species. In a report by Christian et al. (2003), no significant difference was found between acute effects of seismic airgun exposure (a similar impulsive high amplitude noise source to piling; >189 dB re 1 μPa (peak–peak) @ 1 m) upon adult snow crabs Chionoecetes opilio in comparison with control crabs. Another study investigated whether there was a link between seismic surveys and changes in commercial rock lobster Panulirus cygnus based on rates associated with acute to mid-term mortality over a 26-year period. This found no statistically significant correlative link (Parry and Gason, 2006).
171. Sub-lethal physiological effects have been identified from impulsive noise sources including bruised hepatopancreas and ovaries in snow crab exposed to seismic survey noise emissions (at unspecified SPLs) (DFO, 2004). Changes in serum biochemistry and hepatopancreatic cells (Payne et al., 2007), increase in respiration in brown shrimp Crangon crangon (Solan et al., 2016) and metabolic rate changes in green shore crab Carcinus maenas have also been identified.
172. In terms of shellfish eggs and larvae there is no direct evidence to suggest they are at risk of direct harm from high amplitude anthropogenic underwater noise such as piling (Edmonds et al., 2016). Of the few studies that have focussed on the eggs and larvae of shellfish species, evidence of impaired embryonic development and mortality has been found to arise from playback of seismic survey noise among gastropod and bivalve species (De Soto et al., 2013, Nedelec et al., 2014). There is limited information on the effect of impulsive sound upon crustacean eggs, and no research has been conducted on commercially exploited decapod species in the UK. Of the evidence that is available all studies focus on the impact of seismic noise. Preliminary findings show that seismic exposure could be implicated in delayed hatching of snow crab eggs, causing resultant larvae to be smaller than controls (DFO, 2004) and Pearson et al. (1994) found no statistically significant difference between the mortality and development rates of stage II Dungeness crab Metacarcinus magister larvae exposed to single field-based discharges (231 dB re 1 μPa (zero-peak) @ 1 m) from a seismic airgun.
173. While the evidence described above from species specific studies and primarily laboratory based experiments have shown some effects on shellfish species (although lower level effects compared to fish species), another recent study examined the effects on catch rates of European lobster of a temporary closure of lobster fishing grounds during offshore wind farm construction (including piling) (Roach et al., 2018). Monitoring data at the Westermost Rough Offshore Wind Farm located on the north-east coast of England found that the size and abundance of European lobster increased following temporary closure of the area while construction was undertaken. This study shows that the activities associated with construction of the wind farm, which included piling of foundations for 80 wind turbines, did not impact on the resident European lobster populations and instead allowed some respite from fishing activities for a short period time before reopening following construction (Roach et al., 2018). The results of this study strongly suggest that population level injury effects on shellfish species will not occur due to piling operations.

Behaviour

174. Behavioural effects in response to construction related underwater noise include a wide variety of responses including startle responses (also known as C-turn responses), strong avoidance behaviour, changes in swimming or schooling behaviour or changes of position in the water column. The Popper et al. (2014) guidelines provide qualitative behavioural criteria for fish from a range of noise sources. These categorise the risks of effects in relative terms as “high”, “moderate” or “low” at three distances from the source: “near” (i.e. tens of metres), “intermediate” (i.e. hundreds of metres) or “far” (i.e. thousands of metres). The behavioural criteria for piling operations are summarised in Table 9.26   Open ▸ for the four fish groupings.

Table 9.26: Potential Risk for the Onset of Behavioural Effects in Fish from Piling (Popper et al., 2014)a

a Note: Relative risk (high, moderate, low) is given for animals at three distances from the source defined in relative terms as near field (N; i.e. 10s of metres), intermediate (I; i.e. 100s of metres), and far field (F; i.e. 1000s of metres); Popper et al. (2014).

175. Group 1 Fish (e.g. flatfish and elasmobranchs), Group 2 Fish (e.g. salmonids) and shellfish are less sensitive to sound pressure, with these species detecting sound in the environment through particle motion. However, sensitivity to particle motion in fish is also more likely to be important for behavioural responses rather than injury (Hawkins, 2009; Mueller-Blenkle et al., 2010; Hawkins et al., 2014a). Group 3 (including gadoids such as cod and whiting) and Group 4 fish (sprat) are more sensitive to the sound pressure component of underwater noise and, as indicated in Table 9.26   Open ▸ the risk of behavioural effects in the intermediate and far fields are therefore greater for these species.
176. A number of studies have examined the behavioural effects of the sound pressure component of impulsive noise (including piling operations and seismic airgun surveys) on fish species. Mueller-Blenkle et al. (2010) measured behavioural responses of cod and sole to sounds representative of those produced during marine piling, with considerable variation across subjects (i.e. depending on the age, sex, condition etc. of the fish, as well as the possible effects of confinement in cages on the overall stress levels in the fish). This study concluded that it was not possible to find an obvious relationship between the level of exposure and the extent of the behavioural response, although an observable behavioural response was reported at 140 dB to 161 dB re 1 μPa SPLpk for cod and 144 dB to 156 dB re 1 μPa SPLpk for sole. However, these thresholds should not be interpreted as the level at which an avoidance reaction will be elicited, as the study was not able to show this.
177. A study by Pearson et al. (1992) on the effects of geophysical survey noise on caged rockfish Sebastes spp. observed a startle or “C-turn response” at peak pressure levels beginning around 200 dB re 1 μPa, although this was less common with the larger fish. Studies by Curtin University in Australia for the oil and gas industry by McCauley et al. (2000) exposed various fish species in large cages to seismic airgun noise and assessed behaviour, physiological and pathological changes. The study made the following observations:

• a general fish behavioural response to move to the bottom of the cage during periods of high level exposure (greater than RMS levels of around 156 dB to 161 dB re 1 μPa; approximately equivalent to SPLpk levels of around 168 dB to 173 dB re 1 μPa);
• a greater startle response by small fish to the above levels;
• a return to normal behavioural patterns some 14 to 30 minutes after airgun operations ceased;
• no significant physiological stress increases attributed to air gun exposure; and
• some preliminary evidence of damage to the hair cells when exposed to the highest levels, although it was determined that such damage would only likely occur at short range from the source.
  178. The authors did point out that any potential seismic effects on fish may not necessarily translate to population scale effect or disruption to fisheries and McCauley et al. (2000) show that caged fish experiments can lead to variable results. While these studies are informative to some degree, these, and other similar studies, do not provide an evidence base that is sufficiently robust to propose quantitative criteria for behavioural effects (Hawkins and Popper, 2016; Popper et al., 2014) and as such the qualitative criteria outlined in Table 9.26   Open ▸ are proposed.
  179. For the purposes of the underwater noise modelling (volume 3, appendix 10.1), an un-weighted sound pressure level of 150 dB re 1 μPa (RMS) was used as the criterion for indicating the extent of behavioural effects due to impulsive piling based on the Washington State Department of Transport Biological Assessment Preparation for Transport Projects Advanced Training Manual (WSDOT, 2011). At sound pressure levels in excess of 150 dB re 1 μPa (RMS) temporary behavioural changes, such as elicitation of a startle response, disruption of feeding, or avoidance of an area may be expected to occur. It is important to note that this threshold is for onset of potential effects, and not necessarily an ‘adverse effect’ threshold and should be considered alongside other information (including those studies outlined above) in addition to the qualitative criteria set out by Popper et al. (2014) in Table 9.26   Open ▸ . Using this criterion, site specific modelling indicated that behavioural responses may occur to ranges of approximately 17 km for single pile driving and 23 km for concurrent piling (volume 3, appendix 10.1).
  180. Initial outputs of post construction monitoring at the Beatrice Offshore Wind Farm (BOWL, 2021a) concluded that for sandeel there was no evidence of adverse effects on sandeel populations between pre and post construction levels over a six year period (as described in paragraph 80). Cod spawning was also monitored at the same wind farm site (BOWL, 2021b) and similarly, it was concluded that there was no change in the presence of cod spawning between pre and post construction (although spawning intensity was found to be low across both surveys). From these studies, it can be inferred that noise impacts associated with installation of an offshore wind development are temporary and that fish communities (specifically cod and sandeel in this case) show a high degree of recoverability following construction.
  181. As set out in previous sections, information on the impact of underwater noise on marine invertebrates is scarce, and no attempt has been made to set exposure criteria (Hawkins et al., 2014b). Studies on marine invertebrates have shown their sensitivity to substrate borne vibration (Roberts et al., 2016). Aquatic decapod crustaceans are equipped with a number of receptor types potentially capable of responding to the particle motion component of underwater noise (e.g. the vibration of the water molecules which results in the pressure wave) and ground borne vibration (Popper et al., 2001). It is generally their hairs which provide the sensitivity, although these animals also have other sensor systems which could be capable of detecting vibration. It has also been reported that sound wave signature of piling noise can travel considerable distances through sediments (Hawkins and Popper, 2016), with implications for demersal and sediment dwelling fish (e.g. sandeel) and shellfish (e.g. Nephrops) in close proximity to piling operations. Sandeel may be particularly affected by vibration through the seabed during winter hibernation when they remain buried in sandy sediments.
  182. Nephrops have been found to bury less deeply, flush their burrows less regularly and are considerably less active when exposed to impulsive anthropogenic noise (Solan et al., 2016). Nephrops also showed reduced movement and burrowing behaviour in response to simulative shipping and construction noise, however, simulated shipping noise had no effect on the physiology of Nephrops (Solan et al., 2016). Another study on brown shrimp Crangon crangon revealed elevated SPL are implicated in increased incidences of cannibalism and significantly delayed growth (Lagardère and Spérandio, 1981). Simulated shipping noise has been demonstrated to cause some individuals of common shore crab to cease feeding (Wale et al., 2013). The mud crab Scylla paramamosain and European spiny lobsters Palinurus elephas have been reported to have aspects of life history disrupted by anthropogenic noise (e.g. movement and anti-predation behaviour). In contrast to Nephrops, increased movement has been seen in these species in response to simulated shipping noise and offshore activities (Filiciotto et al., 2016; Zhou et al., 2016). Such findings have implications with regard to species fitness, stress and compensatory foraging requirements, along with increased exposure to predators.
  183. However as set out above, monitoring of European lobster catch rates at the Westermost Rough Offshore Wind Farm indicated that population level effects on shellfish species did not occur (Roach et al., 2018). While there may be some residual uncertainty with regard to behavioural effects while piling operations are ongoing, the evidence suggests that long term effects will not occur, and any effects will be reversible.
  184. Scott et al. (2020) provides the most recent review of the existing published literature on the influence of anthropogenic noise and vibration and on crustaceans. The review concluded that some literature sources identified behavioural and physiology effects on crustaceans from anthropogenic noise, however, there were several that showed no effect. The paper notes that to date no effect or influence of noise or vibrations has been reported on mortality rates or fisheries catch rates or yields. In addition, no studies have indicated a direct effect of anthropogenic noise on mortality, immediate or delayed (Scott et al., 2020).

Summary – Marine Species

185. Injury and/or mortality for all fish species is to be expected for individuals within very close proximity to piling operations, shellfish species injury is expected to be similar however there is some evidence injury may occur at smaller ranges as they may be less sensitive to noise impacts. However, this is unlikely to result in significant mortality due to soft start procedures allowing individuals in close proximity to flee the area prior to maximum hammer energy levels which may cause injury to greater ranges.
186. In contrast, behavioural effects are expected over much larger ranges, as discussed above. To illustrate this, Figure 9.6   Open ▸ to Figure 9.9   Open ▸ show the modelled underwater noise levels for SPLpk based on the results from volume 3 appendix 10.1, relative to key fish spawning habitats in the vicinity of the Proposed Development fish and shellfish ecology study area. Figure 9.6   Open ▸ and Figure 9.7   Open ▸ show noise contours for two hammer energies (i.e. the maximum 4,000 kJ hammer energy and the average maximum hammer energy of 3,000 kJ, respectively) at the south-west location and Figure 9.8   Open ▸ and Figure 9.9   Open ▸ show the same for the northern piling location. The north and south-west piling locations were chosen as locations which were closest to the most sensitive habitats/areas: the northern location due to its proximity to herring spawning grounds to the north; the south-west as it is closest to the coastline and most likely to cause barrier effects to diadromous species at that location.
187. Noting that there are no published or agreed thresholds for behavioural effects on fish from piling operations, these figures suggest that behavioural responses will extend over ranges of 10 km to 20 km; for example, assuming avoidance occurs at levels in excess of 160 dB re 1 μPa SPLpk, which is a lower threshold than the levels at which behavioural effects in fish were detected (including McCauley et al., 2000). These results broadly align with qualitative thresholds for behavioural effects on fish as set out in Table 9.26   Open ▸ , with moderate risk of behavioural effects in the range of hundreds of metres to thousands of metres from the piling activity, depending on the species. This is also in line with criterion used in site specific modelling, which predicted behavioural effects to approximately 17 km to 23 km, based on a threshold of 150 dB re 1 μPa (RMS) (see paragraph 179).
188. With respect to marine species, the key habitats for these species are spawning and nursery habitats, as set out volume 3, appendix 9.1. Although spawning and nursery habitats are present within the Proposed Development fish and shellfish ecology study area (see Table 9.11   Open ▸ ) and the ZoI of underwater noise from piling, these habitats extend over a very wide area across the Proposed Development northern North Sea fish and shellfish ecology study area. The relative proportion of these habitats affected by piling operations at any one time will therefore be small in the context of the wider habitat available. Further, as outlined above, piling operations will be temporary and intermittent throughout the construction phase of the Proposed Development.
189. Herring are known to be particularly sensitive to underwater noise and have specific habitat requirements for spawning (see section 9.7 and volume 3, appendix 9.1) which makes them particularly vulnerable to impacts associated with construction related underwater noise. The core herring spawning grounds in the ZoI of the Proposed Development sit to the north of the Proposed Development fish and shellfish ecology study area (see volume 3, appendix 9.1). At maximum hammer energy (4,000 kJ) for the north piling location (closest to mapped herring core spawning grounds), there is minimal overlap of the noise contours into the spawning area (see Figure 9.8   Open ▸ ). Where there is overlap with mapped noise contours, these are at the lower range of noise level (e.g. 130-140 dB re 1 μPa SPLpk) which is considerably lower than levels expected to cause any behavioural effects, as previously discussed.
190. Other species with spawning grounds in the vicinity of the Proposed Development fish and shellfish ecology study area (e.g. sandeel, cod and sprat) have a greater level of overlap with higher noise levels exist within the spawning areas. However, the area of overlap is small in comparison to the extensive nature of the spawning habitats around the Scottish and UK coast. Further, as discussed in paragraph 80, initial outputs of monitoring from the Beatrice Offshore Wind Farm indicate that following cessation of construction operations (including piling) that both cod and sandeel have recovered into any areas potentially affected by construction related underwater noise.
191. Most marine fish IEFs species in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
192. Herring, sprat, cod and sandeel are deemed to be of medium vulnerability, high recoverability and regional to national importance. The sensitivity of the receptor is therefore, considered to be medium.
193. European lobster, Nephrops and edible crab are deemed to be of low vulnerability, high recoverability and regional importance. The sensitivity of the receptor is therefore, considered to be low.

Summary – Diadromous Species

194. As with marine species, diadromous fish species within close proximity to piling operations may experience injury or mortality. However, the nature of diadromous fish species being highly mobile and tending to only utilise the environment within the Proposed Development fish and shellfish ecology study area to pass through during migration, it is unlikely to result in significant mortality of diadromous species. The use of soft start piling procedures (see Table 9.20   Open ▸ ), allowing individuals in close proximity to piling to flee the ensonified area, further reduces the likelihood of injury and mortality on diadromous species.
195. Diadromous fish species may experience behavioural effects in response to piling noise, including a startle response, disruption of feeding, or avoidance of an area. As discussed in preceding sections, these would be expected to occur at ranges of 10 km to 20 km, depending on the species and their relative sensitivities to underwater noise (i.e. in order of lowest to highest sensitivities: lamprey species, Atlantic salmon and sea trout, European eel and shad species). Research from Harding et al. (2016) failed to produce physiological or behavioural responses in Atlantic salmon when subjected to noise similar to piling. However, the noise levels tested were estimated at <160 dB re 1 µPa RMS, below the level at which injury or behavioural disturbance would be expected for Atlantic salmon. Due to the distance between the Proposed Development array area and the coast, these behavioural impacts are unlikely to cause barrier effects between the Proposed Development fish and shellfish ecology study area and the migration routes of diadromous species along the east coast of Scotland, due to the relatively small area around piling events where noise levels are high enough to cause behavioural responses (as demonstrated in Figure 9.6   Open ▸ to Figure 9.9   Open ▸ ). This is the case for both downstream migration of smolts and upstream migration of adults. The low risk of effects on migration of diadromous fish species extends to the freshwater pearl mussel, which is included in the diadromous species section, as part of its life stage is reliant on diadromous fish species including Atlantic salmon and sea trout.
196. Diadromous fish species IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Figure 9.6:  Spawning Habitats for Herring, Sandeel, Sprat and Plaice with Underwater Noise Contours (Unweighted SPLpk) Associated with the Southwest Piling Location at 4,000 kJ Hammer Energy

Figure 9.7:  Spawning Habitats for Herring, Sandeel, Sprat and Plaice with Underwater Noise Contours (Unweighted SPLpk) Associated with the Southwest Piling Location at 3,000 kJ Hammer Energy

Figure 9.8: Spawning Habitats for Herring, Sandeel, Sprat and Plaice with Underwater Noise Contours (Unweighted SPLpk) Associated with the Northern Piling Location at 4,000 kJ Hammer Energy

Figure 9.9:  Spawning Habitats for Herring, Sandeel, Sprat and Plaice with Underwater Noise Contours (Unweighted SPLpk) Associated with the Northern Piling Location at 3,000 kJ Hammer Energy

Significance of the Effect

Marine Species

197. For most fish and shellfish IEF species, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
198. For herring, sprat, cod and sandeel, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
199. For European lobster, Nephrops and edible crab the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

200. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
201. Similarly, for freshwater pearl mussel, as migration of Atlantic salmon and sea trout will not be significantly affected, effects on freshwater pearl mussel will be of negligible adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

202. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Long-term subtidal habitat loss

203. Long-term subtidal habitat loss within the Proposed Development fish and shellfish ecology study area will occur during construction (i.e. through placement of infrastructure) although effects will extend throughout the operation and maintenance phase ( Table 9.15   Open ▸ ). Long-term habitat loss will occur directly under all wind turbine and OSP/Offshore convertor substation platform foundation structures (suction caisson and piled jacket foundations respectively), associated scour protection and cable protection (including at cable crossings) where this is required. The magnitude has been considered for both construction and operation and maintenance phases combined as the structures will be placed during construction and will be in place during the operation and maintenance phase. This impact also considers the habitat loss occurring during the decommissioning phase based on the maximum design scenario that scour and cable protection may be left in situ following decommissioning.

Construction and Operation and Maintenance Phase

Magnitude of Impact

204. The presence of infrastructure within the Proposed Development fish and shellfish ecology study area will result in long term habitat loss. The maximum design scenario is for up to 7,798,856 m2 of long term habitat loss due to the installation of foundations and associated scour protection and cable protection associated with array, OSP/Offshore convertor substation platform interconnector, and offshore export cables. Cable protection will also be required for up to 78 cable crossings for the inter-array and OSP/Offshore convertor substation platform interconnector cables and 16 crossings for the offshore export cable. This equates to a small proportion (0.7%) of the Proposed Development fish and shellfish ecology study area.
205. The long term loss of subtidal habitat involves a change of sediment composition in affected areas (e.g. surrounding foundations and along sections of the Proposed Development array and offshore export cables) from soft sediment habitats (sands, gravels and muds) to hard substrates (foundations, cable protection and scour protection). These areas of habitat loss will be discrete, either in the immediate vicinity of foundations (i.e. foundations and scour protection), or for cable protection these will be relatively small isolated stretches of cable within large areas of sediment which characterise the baseline environment (i.e. soft sediments). This translates into the loss of one type of habitat and the increase of a new habitat. The implications of this are discussed in the sensitivity section (paragraph 207 et seq.) and the potential colonisation of these new substrates is presented and discussed in later assessments of effects (paragraph 259 et seq.). Long-term subtidal habitat loss impacts will occur during the construction phase and will be continuous throughout the 35-year operation and maintenance phase.
206. The impact is predicted to be of local spatial extent (i.e. affecting only a very small proportion of the Proposed Development particularly in the context of the habitats in the wider area), long term duration, continuous and not reversible during the operation and maintenance phase. It is predicted that the impact will affect the receptor directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

Marine Species

207. Fish and shellfish species that are reliant upon the presence of suitable sediment/habitat for their survival are considered to be more vulnerable to change depending on the availability of habitat within the wider geographical region. The seabed habitats removed by the installation of infrastructure will reduce the amount of suitable habitat and available food resource for fish and shellfish species and communities associated with the baseline substrates/sediments however this area represents a low percentage compared with the area of habitats located within the Proposed Development northern North Sea fish and shellfish ecology study area.
208. As confirmed by site specific surveys, the Proposed Development fish and shellfish ecology study area coincides with fish spawning and nursery habitats including plaice, lemon sole, herring, sprat, whiting, cod, haddock, sandeel, mackerel, sprat, Nephrops and elasmobranchs (Coull et al., 1998; Ellis et al., 2012; Aires et al., 2014; see Table 9.11   Open ▸ and volume 3, appendix 9.1). The fish species most vulnerable to habitat loss include sandeel which are demersal spawning species (i.e. eggs are laid on the seabed), as these have specific habitat requirements for spawning (i.e. sandy sediments). This is as identified by the FeAST tool as the pressure ‘Physical change (to another seabed type)’ which has identified that sandeel have high sensitivity to this impact (Wright et al., 2000). As well as laying demersal eggs, sandeel also have specific habitat requirements throughout their juvenile and adult life history and loss of this specific type of habitat could represent an impact on this species. However, monitoring at Horns Rev I, located off the Danish coast, has indicated that the presence of operation wind farm structures has not led to significant adverse effects on sandeel populations in the long term (van Deurs et al., 2012; Stenberg et al., 2011). Initial results of a pre to post construction monitoring study have reported that in some areas of the Beatrice Offshore Wind Farm there was an increase in sandeel abundance (BOWL, 2021a). The findings of a single monitoring study are not able to categorically confirm the conclusion that offshore wind developments are beneficial to sandeel populations; however, it does provide additional evidence that there is no adverse effect on sandeel populations.
209. The Proposed Development fish and shellfish ecology study area also coincides with high intensity sandeel spawning habitat as confirmed by site-specific surveys (see volume 3, appendix 9.1). The presence of infrastructure will result in direct impacts on this habitat, though as detailed above the proportion of habitat affected within the Proposed Development fish and shellfish ecology study area is small and this area is smaller still in the context of the known sandeel habitats (including spawning and nursery habitats) and the potential sandeel habitats in the Proposed Development northern North Sea fish and shellfish ecology study area (volume 3, appendix 9.1).
210. Monitoring at Belgian offshore wind farms has reported that fish assemblages undergo no drastic changes due to the presence of offshore wind farms (Degraer et al., 2020). They reported slight, but significant increases in the density of some common soft sediment-associated fish species (common dragonet Callionymus lyra, solenette Buglossidium luteum, lesser weever Echiichthys vipera and plaice) within the offshore wind farm (Degraer et al., 2020). There was also some evidence of increases in numbers of species associated with hard substrates, including crustaceans (including edible crab), sea bass and common squid (potentially an indication that foundations were being used for egg deposition; Degraer et al., 2020). The author noted that these effects were site specific and therefore may not necessarily be extrapolated to other offshore wind farms, although this does indicate the presence of offshore wind farm infrastructure does not lead to adverse, population wide effects.
211. The Proposed Development fish and shellfish ecology study area is located in the vicinity of known Nephrops spawning habitat, although site specific surveys (including sediment sampling, trawls and seabed imagery) showed that Nephrops habitat was only present along the Proposed Development export cable corridor. Long term habitat loss is predicted to affect a small proportion of this habitat, which will be limited to along the Proposed Development export cable corridor (i.e. array infrastructure is unlikely to affect Nephrops spawning habitat). Lobster spawning and nursery habitats have the potential to occur within the Proposed Development fish and shellfish ecology study area. The proportion of lobster spawning and overwintering habitats affected is, however, likely to be small in the context of the available habitats in this part of the Proposed Development fish and shellfish ecology study area and the wider Proposed Development northern North Sea fish and shellfish ecology study area.
212. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
213. European lobster and Nephrops are deemed to be of high vulnerability, medium to high recoverability and of regional importance. The sensitivity of these fish and shellfish IEFs is therefore considered to be medium.
214. Sandeel are deemed to be of high vulnerability, high recoverability and of national importance. The sensitivity of these fish and shellfish receptor is therefore considered to be medium.
215. Herring are deemed to be of high vulnerability, medium recoverability and of regional importance. However, the sensitivity of herring to this impact is considered to be low, due to the limited suitable spawning sediments overlapping with the Proposed Development fish and shellfish ecology study area and the core herring spawning ground being located well outside the Proposed Development fish and shellfish ecology study area.

Diadromous Species

216. Diadromous fish species are highly mobile and therefore are generally able to avoid areas subject to long term subtidal habitat loss. Diadromous species that are likely to interact with the Proposed Development fish and shellfish ecology study area are only likely to do so by passing through the area during migrations to and from rivers located on the east coast of Scotland (e.g. those designated sites with diadromous fish species listed as qualifying features; see Table 9.12   Open ▸ and volume 3, appendix 9.1). The habitats within the Proposed Development fish and shellfish ecology study area are not expected to be particularly important for diadromous fish species and therefore habitat loss during the construction and operation and maintenance phase of the Proposed Development is unlikely to cause any direct impact to diadromous fish species and would not affect migration to and from rivers.
217. Indirect impacts on diadromous fish species may occur due to impacts on prey species, for example larger fish species for sea lamprey and sandeel for sea trout. As outlined previously for marine species, the majority of large fish species would be able to avoid habitat loss effects due to their greater mobility but would recover into the areas affected following cessation of construction. Sandeel (and other less mobile prey species) would be affected by long term subtidal habitat loss, although recovery of this species is expected to occur quickly as the sediments recover following installation of infrastructure and adults recolonise and also via larval recolonisation of the sandy sediments which dominate the Proposed Development fish and shellfish ecology study area. These sediments are known to recover quickly following cable installation (RPS, 2019). Impacts on diadromous species associated with the creation of new hard substrates are presented and discussed in later assessments of effects (see paragraph 259 et seq.).
218. With reference to the criteria in Table 9.13   Open ▸ and as set out in Table 9.14   Open ▸ , diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the Effect

Marine Species

219. For most fish and shellfish IEF species, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
220. For European lobster and Nephrops, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
221. For sandeel, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

222. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

223. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning Phase

Magnitude of Impact

224. The presence of the infrastructure within the Proposed Development fish and shellfish ecology study area will result in long-term habitat loss. The maximum design scenario is for up to 7,562,609 m2 of permanent habitat loss due to the scour protection associated with wind turbine and OSP/Offshore convertor substation platform foundations and cable protection associated with array, OSP/Offshore convertor substation platform interconnector and offshore export cables being left in situ after decommissioning. This equates to a small proportion (0.6%) of the Proposed Development fish and shellfish ecology study area.
225. The impact is predicted to be of local spatial extent, long term duration, continuous and not reversible. It is predicted that the impact will affect the receptor directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

226. The sensitivity of the fish and shellfish IEFs, for both marine and diadromous species, can be found in the construction and operation and maintenance phase assessment above (paragraph 207 et seq.).

Significance of the effect

Marine Species

227. For most fish and shellfish IEF species, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
228. For European lobster and Nephrops, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
229. For sandeel, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

230. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

231. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Electromagnetic Fields from subsea electrical cabling

232. The installation of inter-array, interconnector and offshore export cables will result in either High Voltage Alternating Current (HVAC) or High Voltage Direct Current (HVDC) under the maximum design scenario (see Table 9.15   Open ▸ ). The conduction of electricity through subsea power cables will result in emission of localised EMFs which could potentially affect the sensory mechanisms of some species of fish and shellfish, particularly electrosensitive species (including elasmobranchs) and diadromous fish species (Centre for Marine and Coastal Studies (CMACS), 2003).

Operation and Maintenance Phase

Magnitude of Impact

233. The presence and operation of inter-array, interconnector and offshore export cables within the Proposed Development fish and shellfish ecology study area will result in emission of localised EMFs affecting fish and shellfish IEFs. EMF comprise both the electrical (E) fields, measured in volts per metre (V/m), and the magnetic (B) fields, measured in microtesla (µT) or milligauss (mG). Background measurements of the magnetic field are approximately 50 μT in the North Sea, and the naturally occurring electric field in the North Sea is approximately 25 μV/m (Tasker et al., 2010).
234. It is common practice to block the direct electrical field (E) using conductive sheathing, meaning that the EMFs that are emitted into the marine environment are the magnetic field (B) and the resultant induced electrical field (iE). It is generally considered impractical to assume that cables can be buried at depths that will reduce the magnitude of the B field, and hence the sediment-sea water interface iE field, to below that at which these fields could be detected by certain marine organisms on or close to the seabed (Gill et al., 2005; Gill et al., 2009). By burying a cable, the magnetic field at the seabed is reduced due to the distance between the cable and the seabed surface as a result of field decay with distance from the cable (CSA, 2019).
235. A variety of design and installation factors affect EMF levels in the vicinity of the cables. These include current flow, distance between cables, cable orientation relative to the earth’s magnetic field (DC only), cable insulation, number of conductors, configuration of cable and burial depth. Clear differences between AC and DC systems are apparent: the flow of electricity associated with an AC cable changes direction (as per the frequency of the AC transmission) and creates a constantly varying electric field in the surrounding marine environment (Huang, 2005). Conversely, DC cables transmit energy in one direction creating a static electric and magnetic field. Average magnetic fields of DC cables are also higher than those of equivalent AC cables ( Table 9.27   Open ▸ ).
236. The strength of the magnetic field (and consequently, induced electrical fields) decreases rapidly horizontally and vertically with distance from source. A recent study conducted by CSA (2019) found that inter-array and offshore export cables buried between depths of 1 m to 2 m reduces the magnetic field at the seabed surface four-fold. For cables that are unburied and instead protected by thick concrete mattresses or rock berms, the field levels were found to be similar to buried cables.
237. CSA (2019) found magnetic field levels directly over live AC undersea power cables associated with offshore wind energy projects range between 65 mG (at seafloor) and 5 mG (1 m above sea floor) for array cables. and 165 mG (at seafloor) and 10 mG (1 m above seafloor) for offshore export cables. At lateral distances from the cable, magnetic fields greatly reduced at the sea floor to between 10 mG and <0.1 mG (from 3 to 7.5 m respectively) for array cables, and at 1 m above the sea floor, magnetic fields reduced to between 15 mG and <0.1 mG (from 3 to 7.5 m respectively) for offshore export cables.
238. The induced electric fields directly over live AC undersea power cables ranged between 1.7 mV/m (at seafloor) and 0.1 mV/m (1 m above seafloor) for array cables and 3.7 mV/m (at seafloor) and 0.2 mV/m (1 m above seafloor) for offshore export cables (CSA, 2019). At lateral distances electric fields at the sea floor reduced to between 0.01 mV/m and 1.1 mV/m (from 3 to 7.5 m respectively) for array cables and 1 m above the sea floor, the magnetic fields reduced to between 0.02 mV/m and 1.3 mV/m (from 3 to 7.5 m respectively) for offshore export cables. This pattern of reduction in the level of magnetic fields with increasing lateral and vertical distance from offshore export cables as described above is visually displayed in Figure 9.10   Open ▸ . Higher colour density of rings demonstrate where magnetic field is strongest, with weaker colour density demonstrating weak magnetic fields (CSA, 2019), with increasing distance from the cable ( Figure 9.10   Open ▸ ).

Figure 9.10: Illustration of Magnetic Field Reduction with Distance, both Laterally and Vertically, from Undersea Inter-array Power Cable (reproduced from CSA, 2019)

239. Normandeau et al. (2011) provided additional data ( Table 9.27   Open ▸ ) demonstrating the rapid drop off of magnetic fields with increasing vertical and horizontal distance from both AC and DC cables. This supports the findings from the CSA (2019) study, with AC cables ranging from 7.85 μT on the seafloor with no horizontal distance to 0.08 μT at 10 m above the seafloor and 10 m horizontal distance. DC cables showed a similar decrease albeit starting from a higher level with cables ranging from 78.27 μT on the seafloor with no horizontal distance to 0.46 μT at 10 m above the seafloor and 10 m horizontal distance.

Table 9.27: Average Magnetic Fields (μT) Generated for AC and DC Offshore Export Cables at Horizontal Distances from the Cable (Assuming Cable Burial to a Depth of 1 m; Source: Modified from Normandeau et al., 2011)

240. The impact is predicted to be of local spatial extent (i.e. within a few metres of buried cables), long term duration, continuous and not reversible during the operation and maintenance phase (impact is reversible upon decommissioning). It is predicted that the impact will affect fish and shellfish IEFs directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

Marine Species

241. Fish and shellfish species (particularly elasmobranchs) are able to detect applied or modified magnetic fields. Species for which there is evidence of a response to E and/or B fields include elasmobranchs (sharks, skates and rays), and plaice (Gill et al., 2005; CSA, 2019). It can be inferred that the life functions supported by an electric sense may include detection of prey, predators or conspecifics to assist with feeding, predator avoidance, and social or reproductive behaviours. Life functions supported by a magnetic sense may include orientation, homing, and navigation to assist with long or short-range migrations or movements (Gill et al., 2005; Normandeau et al., 2011).
242. Studies examining the effects of EMF from AC undersea power cables on fish behaviours have been conducted to determine the thresholds for detection and response to EMF. Table 9.28   Open ▸ provides a summary of the scientific studies conducted to assess sensitivity of EMF on varying fish species.

Table 9.28: Relationship between Geomagnetic Field Detection Electrosensitivity, and the Ability to Detect 50/60-Hz AC Fields in Common Marine Fish and Shellfish Species (Adapted from CSA, 2019)

243. A number of field studies have observed behaviours of fish and other species around AC submarine cables in the U.S.A. (see citations in Table 9.28   Open ▸ ). Observations at three energized 35-kV AC undersea power cable sites off the coast of California that run from three offshore platforms to shore, which are unburied along much of the route, did not show that fish were repelled by or attracted to the cables (Love et al., 2016) (it should be noted that these cables are significantly lower voltage than the maximum design scenario for the Proposed Development). A study investigating the effect of EMF on lesser sandeel larvae spatial distribution found that there was no effect on the larvae (Cresci et al., 2022), and a further study concluded the same for herring (Cresci et al.,2020).
244. Elasmobranchs (i.e. sharks, skates and rays) are known to be the most electro-receptive of all fish. These species possess specialised electro-receptors which enable them to detect very weak voltage gradients (down to 0.5 μV/m) in the environment naturally emitted from their prey (Gill et al., 2005). Both attraction and repulsion reactions to E-fields have been observed in elasmobranch species. Spurdog, an elasmobranch species known to occur within the Proposed Development fish and shellfish ecology study area, avoided electrical fields at 10 μV/cm (Gill and Taylor, 2001), although it should be noted that this level (i.e. 10 μV/cm is equivalent to 1,000 μV/m) is considerably higher than levels associated with offshore electrical cables (see paragraph 238). A COWRIE-sponsored mesocosm study demonstrated that the lesser spotted dogfish and thornback ray were able to respond to EMF of the type and intensity associated with subsea cables; the responses of some ray individuals suggested a greater searching effort when the cables were switched on (Gill et al., 2009). However, the responses were not predictable and did not always occur (Gill et al., 2009). In another study, EMF from 50/60-Hz AC sources appears undetectable in elasmobranchs. Kempster et al. (2013) reported that small sharks could not detect EMF produced at 20 Hz and above, and a magnetic field of 14,300 mG produced by a 50 Hz source had no effect on bamboo shark (Scyliorhinidae, a group that includes catsharks and dogfish) behaviour.
245. Crustacea, including lobster and crab, have been shown to demonstrate a response to B fields, with the Caribbean spiny lobster Panulirus argus shown to use a magnetic map for navigation (CSA, 2019). EMF exposure has been shown to result in varying egg volumes for edible crabs compared to controls. Exposed larvae were significantly smaller, but there were no statistically significant differences in hatched larval numbers, deformities, mortalities, or fitness (Scott, 2019). Exposure to EMF has also been shown to affect a variety of physiological processes within crustaceans. For example, Lee and Weis demonstrated that EMF exposure affected moulting in fiddler crabs (Uca pugilator and Uca pugnax) (Lee and Weis, 1980). Several studies have also suggested that EMFs affect serotonin regulation which may affect the internal physiology of crustaceans potentially leading to behavioural changes, although such changes have not been reported (Atema and Cobb, 1980; Scrivener, 1971). Crab movement and location inside large cages has been reported to be unaffected by proximity to energized AC undersea power cables off southern California and in Puget Sound, indicating crabs also were not attracted to or repelled by energized AC undersea power cables that were either buried or unburied (Love et al., 2016). However, studies on the Dungeness crab and edible crab have reported behavioural changes during exposure to increased EMF and both species showed increased activity when compared to crabs that were not exposed (Scott et al., 2018; Woodruff et al., 2012). Crabs may also spend less time buried, a natural predator avoidance behaviour (Rosaria and Martin, 2010).
246. It is uncertain if other crustaceans including commercially important European lobster and Nephrops are able to respond to magnetic fields in this way. Limited research undertaken with the European lobster found no neurological response to magnetic field strengths considerably higher than those expected directly over an average buried power cable (Normandeau et al., 2011; Ueno et al., 1986). A field study by Hutchison et al. (2018) observed the behaviour of American lobster (a magneto-sensitive species) to DC and AC fields from a buried cable and found that it did not cause a barrier to movement or migration, as both species were able to freely cross the offshore cable route. However, lobsters were observed to make more turns when near the energised cable. Adult lobsters have been shown to spend a higher percentage of time within shelter when exposed to EMF. European lobsters exposed to EMF have also been found to have a significant decrease in egg volume at later stages of egg development and more larval deformities (Scott, 2020).
247. Scott et al. (2020) presents a review of the existing papers on the impact of EMF on crustacean species. Of the papers reviewed by Scott et al. (2020), three studied EMF effects on fauna in the field, the rest were laboratory experiments which directly exposed the target fauna to EMF (Scott et al., 2020). These laboratory experiments, while giving us an indication of crustacean behaviour to EMF, may be less applicable in the context of subsea cables in the marine environment. Of the field experiments, one demonstrated that lobsters have a magnetic compass by tethering lobsters inside a magnetic coil (Lohmann et al., 1995), one focused on freshwater crayfish and put magnets within the crayfish hideouts (Tański et al., 2005), and the last one looked at shore crabs at an offshore wind farm and found no adverse impact on the population. The two former papers are not applicable to offshore wind farm subsea cables and the latter found no adverse impact on the population of shore crabs from the offshore wind farm (Langhamer et al., 2016).
248. Further research by Scott et al. (2021) found that physiological and behavioural impacts on edible crab occurred at 500 μT and 1000 μT, causing disruption to the L-Lactate and D-Glucose circadian rhythm and altering Total Haemocyte Count, and also causing attraction to EMF exposed areas and reduced roaming time. However, these physiological and behavioural effects did not occur at 250 μT. Seeing as even in the event of an unburied cable the maximum magnetic field reported was 78.27 μT (Normandeau et al., 2011), it can be assumed that the magnetic fields generated by the offshore export cables will be lower than 250 μT, and therefore will not present any adverse effects on edible crab. Harsanyi et al. (2022) noted that chronic exposure to EMF effects could lead to physiological deformities and reduced swimming test rates in lobster and edible crab larvae. However, these deformities were in response to EMF levels of 2,800 μT and therefore are higher than EMF effects expected for buried and unburied cables. The report recommends burying of cables in order to reduce any potential impacts associated with high levels of EMF.
249. In summary, the range over which these species can detect electric fields is limited to centimetres, rather than metres, around these species (CSA, 2019). Pelagic species generally swim well above the seafloor and can be expected to rarely be exposed to the EMF at the lowest levels from AC undersea power cables buried in the seafloor, resulting in impacts that would therefore be localised and transient. Demersal species (e.g. skates) that dwell on the bottom, will be closer to the undersea power cables and thus encounter higher EMF levels when near the cable. Demersal species and shellfish are also likely to be exposed for longer periods of time and may be largely constrained in terms of location. However, the rapid decay of the EMF with horizontal distance (i.e. within metres) minimises the extent of potential impacts. Finally, fish that can detect the Earth’s magnetic field are unlikely to be able to detect magnetic fields produced by 50/60-Hz AC power cables and therefore these species are unlikely to be affected in the field (CSA, 2019).
250. Marine fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low (most fish and shellfish IEFs) to medium (decapod crustaceans and elasmobranchs).

Diadromous Species

251. EMF may also interfere with the navigation of sensitive diadromous species. Species for which there is evidence of a response to E and/or B fields include river lamprey, sea lamprey, European eel, and Atlantic salmon (Gill et al., 2005; CSA, 2019). Lampreys possess specialised ampullary electroreceptors that are sensitive to weak, low frequency electric fields (Bodznick and Northcutt, 1981; Bodznick and Preston, 1983), but information regarding what use they make of the electric sense is limited. Chung-Davidson et al. (2008) found that weak electric fields may play a role in the reproduction of sea lamprey and it was suggested that electrical stimuli mediate different behaviours in feeding-stage and spawning-stage individuals. This study (Chung-Davidson et al., 2008) showed that migration behaviour of sea lamprey was affected (i.e. adults did not move) when stimulated with electrical fields of intensities of between 2.5 and 100 mV/m, with normal behaviour observed at electrical field intensities higher and lower than this range. It should be noted, however, that these levels are considerably higher than modelled induced electrical fields expected from AC subsea cables (see Table 9.27   Open ▸ ).
252. Atlantic salmon and European eel have both been found to possess magnetic material of a size suitable for magnetoreception, and these species can use the earth’s magnetic field for orientation and direction finding during migration (Gill and Bartlett, 2010; CSA, 2019). Mark and recapture experiments undertaken at the Nysted operation offshore wind farm showed that eel did cross the offshore export cable (Hvidt et al., 2003) but studies on European eel in the Baltic Sea have highlighted some limited effects of subsea cables (Westerberg and Lagenfelt, 2008). The swimming speed during migration was shown to change in the short term (tens of minutes) with exposure to AC electric subsea cables, even though the overall direction remained unaffected (Westerberg and Langenfelt, 2008). The authors concluded that any delaying effect (i.e. on average 40 minutes) would not be likely to influence fitness in a 7,000 km migration. Research in Sweden on the effects of a HVDC cable on the migration patterns of a range of fish species, including salmonids, failed to find any effect (Westerberg et al., 2007; Wilhelmsson et al., 2010). Research conducted at the Trans Bay cable, a DC undersea cable near San Francisco, California, found that migration success and survival of chinook salmon (Oncorhynchus tshawytscha) was not impacted by the cable. However, as with the Hutchison et al. (2018) study on lobster (paragraph 246), behavioural changes were noted when these fish were near the cable (Kavet et al., 2016) with salmon appearing to remain around the cable for longer periods. These studies demonstrate that while DC undersea power cables can result in altered patterns of fish behaviour, these changes are temporary and do not interfere with migration success or population health.
253. Table 9.29   Open ▸ provides a summary of the scientific studies conducted to assess sensitivity of EMF on varying fish species.

Table 9.29: Relationship between Geomagnetic Field Detection Electrosensitivity, and the Ability to Detect 50/60-Hz AC Fields in Diadromous Fish Species (Adapted from CSA, 2019)

254. Diadromous fish IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the Effect

Marine Species

255. For most fish and shellfish IEF species, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
256. For European lobster Nephrops edible crab and elasmobranchs, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

257. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

258. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Colonisation of foundations, scour protection and cable protection

259. Foundation, cable protection and scour protection components of offshore wind farms can be viewed as artificial reefs, as these add hard substrate to areas typically characterised by soft, sedimentary environments. Man-made structures placed on the seabed attract many marine organisms including benthic species normally associated with hard substrates and therefore, may have indirect effects on fish and shellfish populations through their potential to act as artificial reefs and to bring about changes to food resources (Inger et al., 2009). Additionally, man-made structures may also have direct effects on fish through their potential to act as fish aggregation devices (Petersen and Malm, 2006).

Operation and Maintenance Phase

Magnitude of Impact

260. The presence of infrastructure within the Proposed Development fish and shellfish ecology study area may result in the colonisation of foundations, scour protection and cable protection. The maximum design scenario is for up to 10,198,971 m2 of habitat created due to the installation of jacket foundations, associated scour protection and cable protection associated with inter-array cables, OSP/Offshore convertor substation platform interconnector cables and offshore export cables ( Table 9.15   Open ▸ ). This value however is likely an over estimation of habitat creation as it is based on solid panels being used for the 317 jacket foundations. The four sides of these jackets will be made of a lattice structure; however the precise dimensions of these lattices are unknown at the time of writing, therefore a solid structure has been assumed from the values available, noting that this will result in an overestimate of the habitat created. It is expected that the foundations and scour and cable protection will be colonised by species already occurring in the benthic subtidal and intertidal ecology study area (e.g. tunicates, bryozoa sp., mussels and barnacles which are typical of temperate seas; see volume 2, chapter 8). The increased availability of prey species may lead to increased numbers of fish and shellfish species utilising the additional prey resource and hard substrate habitats. In addition, this may lead to further effects to higher trophic levels, including marine mammals and birds, the implications of which are further discussed in volume 2, chapter 10 and volume 2, chapter 11.
261. These effects are only considered in the operation and maintenance phase as it takes time for organisms to colonisation a structure post-installation.
262. The impact is predicted to be of local spatial extent, long term duration (35-year operation phase), continuous and medium reversibility. It is predicted that the impact will affect the receptor both directly and indirectly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

Marine Species

263. Hard substrate habitat created by the introduction of wind turbine foundations and scour/cable protection are likely to be primarily colonised within hours or days after construction by demersal and semi-pelagic fish species (Andersson, 2011). Continued colonisation has been seen for a number of years after the initial construction, until a stratified recolonised population is formed (Krone et al., 2013). Feeding opportunities or the prospect of encountering other individuals may attract fish aggregate from the surrounding areas, which may increase the carrying capacity of the area (Andersson and Öhman, 2010; Bohnsack, 1989).
264. The dominant natural substrate character of the Proposed Development fish and shellfish ecology study area (e.g. soft sediment or hard rocky seabed) will determine the number of new species found on the introduced vertical hard surface and associated scour protection. When placed on an area of seabed which is already characterised by rocky substrates, few species will be added to the area, but the increase in total hard substrate could sustain higher abundance (Andersson and Öhman, 2010). Conversely, when placed on a soft seabed, most of the colonising fish will be normally associated with rocky (or other hard bottom) habitats, thus the overall diversity of the area may increase (Andersson et al., 2009). A new baseline species assemblage will be formed via recolonisation and the original soft-bottom population will be displaced (Desprez, 2000). This was observed in studies by Leonhard et al. (Danish Energy Agency, 2012) at the Horns Rev offshore wind farm, and Bergström et al. (2013) at the Lillgrund offshore wind farm. An increase in fish species associated with reefs such as goldsinny wrasse Ctenolabrus rupestris, lumpsucker Cycloplerus lumpus and eelpout Zoarces viviparous, and a decrease in the original sandy-bottom fish population were reported (Danish Energy Agency, 2012; Bergström et al., 2013). A decrease in soft sediment species is contradictory to findings of Degraer et al. (2020) where an increase in density of soft sediment species was seen, although this increase may be related to reduced fishing pressure within the array. However it is noted by Degraer et al. (2020) that these effects were site specific and therefore may not necessarily be extrapolated to other offshore wind farms (see paragraph 210 for further information on increases of crustacean species associated with installation of an offshore wind development).
265. The longest monitoring programme conducted to date at the Lillgrund offshore wind farm in the Öresund Strait in southern Sweden, showed no overall increase in fish numbers, although redistribution towards the foundations within the offshore wind farm area was noticed for some species (i.e. cod, eel and eelpout; Andersson, 2011). More species were recorded after construction than before, which is consistent with the hypothesis that localised increases in biodiversity may occur following the introduction of hard substrates in a soft sediment environment. Overall, results from earlier studies reported in the scientific literature did not provide robust data (e.g. some were visual observations with no quantitative data) that could be generalised to the effects of artificial structures on fish abundance in offshore wind farm areas (Wilhelmsson et al., 2010). More recent papers are, however, beginning to assess population changes and observations of recolonisation in a more quantitative manner (Krone et al., 2013).
266. There is uncertainty as to whether artificial reefs facilitate recruitment in the local population, or whether the effects are simply a result of concentrating biomass from surrounding areas (Inger et al., 2009). Linley et al. (2007) concluded that finfish species were likely to have a neutral to beneficial likelihood of benefitting, which is supported by evidence demonstrating that abundance of fish can be greater within the vicinity of wind turbine foundations than in the surrounding areas, although species richness and diversity show little difference (Wilhelmsson et al., 2006a; Inger et al., 2009). A number of studies on the effects of vertical structures and offshore wind farm structures on fish and benthic assemblages have been undertaken in the Baltic Sea (Wilhelmsson et al., 2006a; 2006b). These studies have shown evidence of increased abundances of small demersal fish species (including gobies Gobidae, and goldsinny wrasse) in the vicinity of structures, most likely due to the increase in abundance of epifaunal communities which increase the structural complexity of the habitat (e.g. mussels and barnacles Cirripedia spp.). It was speculated that in true marine environments (e.g. the North Sea), offshore wind farms may enhance local species richness and diversity, with small demersal species such as gobies providing prey items for larger, commercially important species including cod (which have been recorded aggregating around vertical steel constructions in the North Sea; Wilhelmsson et al., 2006a). Monitoring of fish populations in the vicinity of an offshore wind farm off the coast of the Netherlands indicated that the offshore wind farm acted as a refuge for at least part of the cod population (Lindeboom et al., 2011; Winter et al., 2010).
267. In contrast, post construction fisheries surveys conducted in line with the Food and Environmental Protection Act (FEPA) licence requirements for the Barrow and North Hoyle offshore wind farms, found no evidence of fish abundance across these sites being affected, either beneficially or adversely, by the presence of the offshore wind farms (Cefas, 2009; BOWind, 2008) therefore suggesting that any effects, if seen, are likely to be highly localised and while of uncertain duration, the evidence suggests effects are not adverse.
268. It is likely that the greatest potential for beneficial effects exist for crustacean species, such as crab and lobster, due to expansion of their natural habitats (Linley et al., 2007) and the creation of additional refuge areas. Where foundations and scour protection are placed within areas of sandy and coarse sediments, this will represent novel habitat and new potential sources of food in these areas and could potentially extend the habitat range of some shellfish species. Post-construction monitoring surveys at the Horns Rev offshore wind farm noted that the hard substrates were used as a hatchery or nursery grounds for several species, and was particularly successful for brown crab (BioConsult, 2006). They concluded that larvae and juveniles rapidly invade the hard substrates from the breeding areas (BioConsult, 2006). As both crab and lobster are commercially exploited in the vicinity of the Proposed Development fish and shellfish ecology study area, there is potential for benefits to the fisheries, depending on the materials used in construction of the offshore wind farm.
269. Other shellfish species, such as the blue mussel Mytilus edulis, have the potential for great expansion of their normal habitat due to increased hard substrate in areas of sandy habitat. Krone et al. (2013) coined the term 'Mytilusation' to describe this mass biofouling process recorded at a platform in the German Bight, North Sea. It was found that over a three-year period, almost the entire vertical surface of area of the platform piles had been colonised by three key species blue mussel, the amphipod Jassa spp. and anthozoans (mainly Metridium senile). These three species were observed to occur in depth-dependant bands, attracting pelagic fish species such as horse mackerel Trachurus trachurus and demersal pouting Trisopterus luscus in great numbers. Layers of shell detritus were visible at the base of the foundations due to the mussel populations above and both velvet swimming crab and brown crabs were recorded here. These species were not typical of baseline species assemblage, providing further evidence of localised changes in fish and shellfish assemblages in the vicinity of foundation structures.
270. The colonisation of new habitats may potentially lead to the introduction of invasive and non-native species species (see volume 2, chapter 8 for detailed discussion). With respect to fish and shellfish populations, this may have indirect adverse effects on shellfish populations as a result of competition. However, no invasive and non-native species species were identified as present in the area during surveys across the Proposed Development fish and shellfish ecology study area. There is little evidence of adverse effects on fish and shellfish IEFs resulting from colonisation of other offshore wind farms by invasive and non-native species species. The post construction monitoring report for the Barrow offshore wind farm demonstrated no evidence of invasive and non-native species species on or around the monopiles (EMU, 2008a), and a similar study of the Kentish Flats monopiles only identified slipper limpet Crepidula fornicata (EMU, 2008b). Potential adverse effects of the introduction of invasive and non-native species species are discussed in detail in volume 2, chapter 8.
271. Marine fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, and local to national importance (recoverability is not relevant to this impact during the operation maintenance phase). The sensitivity of the receptor is therefore, considered to be low.

Diadromous Species

272. Diadromous species that are likely to interact with the Proposed Development fish and shellfish ecology study area are only likely to do so by passing through the area during migrations to and from rivers located on the east coast of Scotland, such as to rivers with designated sites, with diadromous fish species listed as qualifying features, as presented in volume 3, appendix 9.1. In most cases, it is expected that diadromous fish are unlikely to utilise the increase in hard substrate within the Proposed Development fish and shellfish ecology study area for feeding or shelter opportunities as they are only likely to be in the vicinity when passing through during migration.
273. However, there is potential for impacts upon diadromous fish species resulting from increased predation by marine mammal species within offshore wind farms. Tagging of harbour seal Phoca vitulina and grey seal Halichoerus grypus around Dutch and UK wind farms provided significant evidence that the seal species were utilising wind farm sites as foraging habitats (Russel et al., 2014), specifically targeting introduced structures such as wind turbine foundations. However, a further study using similar methods concluded that there was no change in behaviour within the wind farm (McConnell et al., 2012), so it is not certain exactly to what extent seals utilise offshore wind developments and therefore effects may be site specific. Assuming that seals do utilise offshore wind developments as foraging areas, diadromous fish species may be impacted by the increased predation in an area where predation was lower prior to development. It is, however, unlikely that this would result in significant predation on diadromous species. Research has shown that Atlantic salmon smolts spend little time in the coastal waters, and instead are very active swimmers in coastal waters, making their way to feeding grounds in the north quickly (Gardiner et al., 2018a; Gardiner et al., 2018a; Newton et al., 2017; Newton et al., 2019; Newton et al., 2021) (see volume 3, appendix 9.1 for further detail on Atlantic salmon migration). Due to the evidence that Atlantic salmon tend not to forage in the coastal waters of Scotland, it is unlikely that they will spend time foraging around wind turbine foundations and therefore are at low risk of impact from increased predation from seals and other predators.
274. Sea trout may be at higher risk of increased predation from seals than Atlantic salmon due to their higher usage of coastal environments. Sea trout are generalist, opportunistic feeders with their diet comprising mainly of fish, crustaceans, polychaetes and surface insects with proportion of each of these prey categories varying dependent on season (Rikardsen et al., 2006; Knutsen et al., 2001). Due to the potential for increase in juvenile crustacean species and other shellfish species (see paragraphs 268 and 269) which are potential prey items from sea trout, it is possible that foraging sea trout may be attracted to the hard substrates introduced by installation of the Proposed Development. This attraction could in turn lead to increased predation of seal species upon sea trout species. However, there is little evidence at present documenting an increased abundance of sea trout around wind turbine foundations (increases in fish abundance tend to be hard bottom dwelling fish species), therefore the above effect of increased prey items attracting sea trout is yet to be recorded. Further, the Proposed Development fish and shellfish ecology study area is situated in an area of high sandeel abundance, and it is likely that sandeel will make up a considerable proportion of sea trout diet when in the marine environment (Svenning et al., 2005; Thorstad et al., 2016). Sandeel species are unlikely to be associated with wind turbine structures due to habitat preferences (discussed in volume 3, appendix 9.1) and therefore sea trout may be less likely to be attracted to increased prey availability colonised on hard substrates, when there is an abundance of prey species which is not associated with the installation of hard substrate.
275. The low risk of effects on diadromous fish species extends to the freshwater pearl mussel, which is included in the diadromous species section, as part of its life stage is reliant on diadromous fish species including Atlantic salmon and sea trout.
276. Sea lamprey are parasitic in their marine phase, feeding off larger fish and marine mammals (Hume, 2017). As such it is not expected that they will be particularly attracted to structures associated with offshore wind developments. However, this is not certain, as there is limited information available on the utilisation of the marine environment by sea lamprey.
277. Most diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.
278. Atlantic salmon and sea lamprey are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.
279. Sea trout are deemed to be of medium vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the Effect

Marine Species

280. Overall for IEF species, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms. This is likely to be a conservative prediction as there is some evidence (although with uncertainties) that some fish and shellfish populations are likely to benefit from introduction of hard substrates.

Diadromous Species

281. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

282. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning Phase

Magnitude of Impact

283. During the decommissioning phase, some infrastructure is assumed to be left in situ within the Proposed Development fish and shellfish ecology study area with the impact of colonisation of infrastructure continuing in perpetuity following decommissioning. The maximum design scenario assumes that up to 7,493,186 m2 of scour and cable protection will remain post decommissioning with all foundation structures removed during decommissioning (see Table 9.15   Open ▸ ). This equates to a small proportion (0.6%) of the Proposed Development fish and shellfish ecology study area.
284. The impact is predicted to be of local spatial extent, permanent duration, continuous and not reversible. It is predicted that the impact will affect fish and shellfish receptors directly. The magnitude is therefore considered to be low.

Sensitivity of the Receptor

285. The sensitivity of all fish and shellfish IEFs, for both marine and diadromous species, can be found in the construction and operation and maintenance phase assessment above (paragraph 271 et seq.) and are concluded to be low.

Significance of the effect

Marine Species

286. Overall for IEF species, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

287. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

288. No additional fish and shellfish ecology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

9.11.1.              Proposed Monitoring

289. This section outlines the proposed monitoring proposed for fish and shellfish ecology. Proposed monitoring measures are outlined in Table 9.30   Open ▸ .

Table 9.30: Monitoring Commitments for Fish and Shellfish Ecology

9.12.   Cumulative Effects Assessment

9.12. Cumulative Effects Assessment

9.12.1.              Methodology

290. The CEA assesses the impact associated with the Proposed Development together with other relevant plans, projects and activities. Cumulative effects are therefore the combined effect of the Proposed Development in combination with the effects from a number of different projects, on the same receptor or resource. Please see volume 1, chapter 6 for detail on CEA methodology.
291. The projects and plans selected as relevant to the CEA presented within this chapter are based upon the results of a screening exercise (see volume 3, appendix 6.4 of the Offshore EIA Report). Volume 3, appendix 6.4 further provides information regarding how information pertaining to other plans and projects is gained and applied to the assessment. Each project or plan has been considered on a case by case basis for screening in or out of this chapter's assessment based upon data confidence, effect-receptor pathways and the spatial/temporal scales involved.
292. In undertaking the CEA for the Proposed Development, it is important to bear in mind that other projects and plans under consideration will have differing potential for proceeding to an operation stage and hence a differing potential to ultimately contribute to a cumulative impact alongside the Proposed Development. Therefore, a tiered approach has be adopted. This provides a framework for placing relative weight upon the potential for each project/plan to be included in the CEA to ultimately be realised, based upon the project/plan’s current stage of maturity and certainty in the projects’ parameters. The tiered approach which will be utilised within the Proposed Development CEA employs the following tiers:

• tier 1 assessment – Proposed Development (Berwick Bank Wind Farm offshore) with Berwick Bank Wind Farm onshore;
• tier 2 assessment – All plans/projects assessed under Tier 1, plus projects which became operational since baseline characterisation, those under construction, those with consent and submitted but not yet determined;
• tier 3 assessment – All plans/projects assessed under Tier 2, plus those projects with a Scoping Report; and
• tier 4 assessment – All plans/projects assessed under Tier 3, which are reasonably foreseeable, plus those projects likely to come forward where an Agreement for Lease (AfL) has been granted.
  293. The specific projects scoped into the CEA for fish and shellfish ecology, are outlined in Table 9.31   Open ▸ .
  294. Due to the uncertainty regarding assessment of projects in the far future including when projects may be decommissioned and what activities this might involve it has been assumed that the magnitude of impact from decommissioning is likely to be similar or substantially less than those experienced for the construction phase. As a result, no cumulative assessments of decommissioning phases have been undertaken.
  295. As described in volume 1, chapter 3, the Applicant is developing an additional export cable grid connection to Blyth, Northumberland (the Cambois connection). Necessary consents (including marine licences) will be applied for separately. The CEA for the Cambois connection is based on information presented in the Cambois connection Scoping Report (SSER, 2022e), submitted in October 2022. The Cambois connection has been scoped into the CEA for fish and shellfish ecology on the basis that Cambois connection will overlap spatially and temporally with the Proposed Development and the project will engage in activities such as cable burial and installation of cable protection which will impact fish and shellfish IEFs.
  296. The range of potential cumulative impacts that are identified and included in Table 9.32   Open ▸ , is a subset of those considered for the Proposed Development alone assessment. This is because some of the likely significant effects identified and assessed for the Proposed Development alone, are localised and temporary in nature. It is considered therefore, that these potential impacts have limited or no potential to interact with similar changes associated with other plans or projects. These have therefore been scoped out of the cumulative effects assessment.
  297. Similarly, some of the potential impacts considered within the Proposed Development alone assessment are specific to a particular phase of development (e.g. construction, operation and maintenance or decommissioning). Where the potential for cumulative effects with other plans or projects only have potential to occur where there is spatial or temporal overlap with the Proposed Development during certain phases of development, impacts associated with a certain phase may be omitted from further consideration where no plans or projects have been identified that have the potential for cumulative effects during this period.
  298. For the purposes of the fish and shellfish ecology assessment of effects, cumulative effects have been assessed within a representative 25 km buffer of the Proposed Development fish and shellfish ecology study area which encompasses the areas within two tidal excursions ( Figure 9.11   Open ▸ ). This buffer, which is based on two tidal excursions from the Proposed Development fish and shellfish ecology study area, is considered appropriate as the majority of impacts considered in section 9.11 will be localised in extent and this encompasses all projects in the Forth and Tay region. This approach aligns with that taken for Benthic Subtidal and Intertidal Ecology (volume 2, chapter 8) and Physical Processes (volume 2, chapter 7). The only exception to this is underwater noise during the construction phase, where a larger buffer of 100 km has been used to account for the larger ZoI of this impact (i.e. behavioural effects to ranges of tens of km from the Proposed Development fish and shellfish ecology study area).
  299. All impacts that have been identified as having potential cumulative effects have been assessed at the appropriate phases of development in the following sections. Cumulative impacts of increased SSC and associated deposition for the operation and maintenance phase (for both the Proposed Development and cumulative projects) have been excluded from the cumulative assessment. This is due to operation and maintenance activities being of much lower magnitude than construction impacts, being limited to reburial/repair of cables, rather than installation of hundreds of km of cable. Further, there is a relatively low likelihood of cumulative projects operation and maintenance activities occurring at the same time however, there is minimal spatial overlap between projects and due to the relative local scale of SSC impacts it is unlikely that in the event of concurrent maintenance activities, SSC plumes would interact causing a cumulative effect.

Table 9.31: List of Other Developments Considered Within the CEA for Fish and Shellfish Ecology

Figure 9.11: Other Projects/Plans Screened into the Cumulative Effects Assessment for Fish and Shellfish Ecology

9.12.2.              Maximum Design Scenario

300. The maximum design scenarios identified in Table 9.32   Open ▸ have been selected as those having the potential to result in the greatest effect on an identified IEF or receptor group. The cumulative effects presented and assessed in this section have been selected from the details provided in volume 1, chapter 3 of the Offshore EIA Report as well as the information available on other projects and plans (see volume 3, appendix 6.4), to inform a ‘maximum design scenario’. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the PDE (e.g. different wind turbine layout), to that assessed here, be taken forward in the final design scheme.

Table 9.32: Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Cumulative Effects on Fish and Shellfish Ecology

9.12.3.              Cumulative Effects Assessment

301. An assessment of the likely significance of the cumulative effects of the Proposed Development upon fish and shellfish ecology IEFs arising from each identified impact is given below.

Cumulative Temporary subtidal Habitat Loss/Disturbance

Tier 2

Construction phase

Magnitude of impact

302. The construction and operation and maintenance of the projects/plans/activities shown in Table 9.32   Open ▸ may lead to cumulative temporary subtidal habitat loss/disturbance within the fish and shellfish ecology CEA study area. Table 9.33   Open ▸ presents the areas of habitat loss for each project. This total area is highly conservative as the majority of the disturbance would not occur at the same time, rather small proportions of habitat loss would occur across the CEA study area over the construction phase for the Proposed Development.
303. Table 9.32   Open ▸ and Figure 9.11   Open ▸ shows all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable Corridor, Eastern Link 1, Eastern Link 2 and Eyemouth disposal site. There is small overlap between construction phase for the Proposed Development and Inch Cape Offshore Wind Farm and Seagreen 1A Project as well as the operation and maintenance phases once construction has completed. The remaining projects will be in their operation and maintenance phase during the Proposed Development construction phase. The total cumulative temporary subtidal habitat loss is 145,325,450 m2, however this number is highly conservative as habitat loss associated operation and maintenance will be spread over the entirety of the phase, and therefore there will only be a small proportion of this habitat loss happening at any one time.
304. Table 9.33   Open ▸ shows the cumulative temporary habitat loss/disturbance within a 25 km buffer for all projects in the Tier 2 assessment, noting that the Seagreen 1A assessment does not provide estimates for temporary habitat loss/disturbance associated with operation and maintenance (Seagreen Wind Energy, 2012). The values for temporary habitat disturbance/loss during the construction of the Seagreen 1A Project are presented in Table 9.33   Open ▸ and have been produced by undertaking a separate assessment to determine the maximum design scenario for this project using the following publicly available datasets (Seagreen Wind Energy, 2012b[6]; Seagreen Wind Energy, 2022[7]; and Seagreen Wind Energy 2020[8]). These values have then been subtracted from those provided in the Seagreen 1 assessment (Seagreen Wind Energy, 2012a) to calculate the maximum design scenario for Seagreen 1, to prevent double counting and to ensure these projects are assessed separately and proportionately.
305. There is also expected to be temporary habitat disturbance from the construction and operation and maintenance of Eastern Link 1 and 2. The environmental appraisal for Eastern Link 1 does not give a specific value for temporary habitat loss in the project however it is expected to include a pre-installation footprint of 50 m and a 30 m footprint for cable installation. Additionally, only 24% of the 176 km Eastern Link 1 cable will be within the Proposed Development fish and shellfish ecology study area therefore only a proportion of the overall impact will be cumulative. Table 9.33   Open ▸ shows that in the construction phase Eastern Link 2 will result in 15,200,000 m2 of temporary habitat disturbance however only 18% of the 436 km cables will occur with the Proposed Development fish and shellfish ecology study area.
306. There is potential for cumulative impacts to arise with disposal activities at the Eyemouth disposal site. The total area of the site is 664,761 m2 (see Table 9.33   Open ▸ ), however only a very small portion of this would be affected at any one time by an individual disposal event.
307. The maximum design scenario for habitat loss from the cumulative offshore wind farms, and the Eyemouth disposal site has been considered in this cumulative assessment. However, as noted above, this is considered to be highly precautionary as activities associated with the operation and maintenance phase of wind farms occur intermittently throughout the phase and therefore are unlikely to completely overlap with the construction phase of the Proposed Development.
308. The cumulative impact is predicted to be of regional spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the fish and shellfish IEFs directly. Given the minor temporal overlap in construction activities and that the operation and maintenance activities associated with the relevant projects will not add substantially to the total footprint associated with the Proposed Development and with only a proportion of the operation and maintenance operations occurring during the construction phase of the Proposed Development or overlapping during the operation and maintenance operations, the magnitude of the impact will not be greater than that assumed for the project alone. The magnitude is therefore, considered to be low.

Table 9.33:  Total Area and Component Parts of Temporary Habitat Loss/Disturbance of the Relevant Cumulative Impact Projects in the Construction Phase of the Proposed Development

Sensitivity of receptor

309. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 70 to 89.

Marine Species

310. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area and wider Proposed Development northern North Sea fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
311. European lobster and Nephrops are deemed to be of high vulnerability, medium to high recoverability and of regional importance. The sensitivity of these fish and shellfish receptors is therefore considered to be medium.
312. Herring are deemed to be of high vulnerability, medium recoverability and of regional importance. However, the sensitivity of herring to this impact is considered to be low, due to the limited suitable spawning sediments overlapping with the Proposed Development fish and shellfish ecology study area and the core herring spawning ground being located well outside the Proposed Development fish and shellfish ecology study area.
313. Sandeel are deemed to be of high vulnerability, high recoverability and of national importance. The sensitivity of sandeel is therefore considered to be medium.

Diadromous Species

314. Diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of effect

Marine Species

315. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of most fish and shellfish IEFs (including herring) is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
316. For sandeel, the magnitude of the cumulative effect is deemed to be low and the sensitivity is considered to be medium. Given the minor temporal overlap in construction activities and the operation and maintenance activities associated with the relevant projects, these will not add substantially to the total footprint associated with the Proposed Development. With only a small proportion of the operation and maintenance operations occurring during the construction phase of the Proposed Development and spread over a much larger area than the Proposed Development alone, the significance of the effect will not be greater than that assumed for the project alone. The effect will, therefore, be of minor adverse significance which is not significant in EIA terms.
317. For Nephrops and European lobster, the magnitude of the cumulative impact is deemed to be low and the sensitivity is considered to be medium. However, the significance of effect will not be greater than that assumed for the Proposed Development alone for the reasons outlined above.

Diadromous Species

318. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

319. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Operation and maintenance phase

Magnitude of impact

320. The operation and maintenance activities of the cumulative projects will overlap with the operation and maintenance phase of the Proposed Development and may lead to temporary subtidal habitat loss/disturbance of up to 32,276,397 m2.
321. Table 9.32   Open ▸ and Figure 9.11   Open ▸ shows all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable Corridor, Eastern Link 1, Eastern Link 2 and Eyemouth disposal site.
322. During the operation and maintenance phase of the Proposed Development, the other Tier 2 wind farms will reach their decommissioning age before the Proposed Development reaches its decommissioning age in 2066. The operation lifetime of Inch Cape is expected to be up to 35 years, with construction ending in 2025 and decommissioning expected in 2060 (Inch Cape Offshore Limited, 2018). The operation lifetime of Neart na Gaoithe is expected to be 25 years, with construction ending in 2023 and decommissioning expected in 2048 (Mainstream Renewable Power, 2019). Seagreen 1 and Seagreen 1A Project has an operation and maintenance phase of 25 – 30 years which will lead to its decommissioning in 2048 – 2053 (Seagreen Wind Energy, 2012).
323. The maximum design scenario for habitat loss from the cumulative offshore wind farms has been considered in this cumulative assessment, with the total areas of seabed affected by this impact presented in Table 9.34   Open ▸ . However, this is considered to be precautionary as activities associated with the operation and maintenance of the Proposed Development (and the other developments considered here) will occur intermittently throughout the lifetime of the Proposed Development and therefore are unlikely to completely overlap with the decommissioning periods of the other offshore wind farms. Furthermore, Inch Cape Offshore Wind Farm and Neart na Gaoithe Offshore Wind Farm assume in their environmental statements that the decommissioning process will produce similar levels of temporary habitat disturbance to their construction phase however this is likely to be an over estimation because not all of the infrastructure is likely to be removed from the seabed in the final plans (Inch Cape Offshore Limited, 2018; Mainstream Renewable Power, 2019). The EIA for Seagreen 1 however does not make this assumption and provide specific values (Seagreen Wind Energy, 2012). Values for the Seagreen 1A Project have been determined by the project specific assessment undertaken by RPS (further detail in paragraph 304).
324. The environmental assessment for Seagreen 1A Export Cable Corridor provides no values for the operation and maintenance of the cable; however, it is expected to be small in comparison with the Proposed Development and the other offshore wind farms considered. The impacts during decommissioning are expected to be similar, and less significant, than those predicted during installation (Seagreen Wind Energy Ltd., 2021).
325. The environmental appraisals for Eastern Link 1 (National Grid Electricity Transmission and Scottish Power Transmission, 2022) and Eastern Link 2 (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022) do not provide detail regarding the temporary habitat disturbance of their maintenance activities. They do however expect it to be highly reduced from the construction phase and repair works are likely to be highly localised to the area of concern and therefore the spatial extent of any impacts would be small in extent.
326. Currently it is unknown when the Eyemouth disposal site may close therefore to ensure the worst-case scenario it has been assumed it will still be open and the area of temporary habitat loss can be seen in Table 9.34   Open ▸ (Marine Scotland, 2018).
327. The cumulative impact is predicted to be of local spatial extent, short term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Table 9.34: Total Area and Component Parts of Temporary Habitat Loss/Disturbance of the Relevant Cumulative Projects in the Operation and Maintenance Phase of the Proposed Development

Sensitivity of the receptor

328. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 70 to 89.

Marine Species

329. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
330. European lobster and Nephrops are deemed to be of high vulnerability, medium to high recoverability and of regional importance. The sensitivity of these fish and shellfish IEFs is therefore considered to be medium.
331. Herring are deemed to be of high vulnerability, medium recoverability and of regional importance. However, the sensitivity of herring to this impact is considered to be low, due to the limited suitable spawning sediments overlapping with the Proposed Development fish and shellfish ecology study area and the core herring spawning ground being located well outside the Proposed Development fish and shellfish ecology study area.
332. Sandeel are deemed to be of high vulnerability, high recoverability and of national importance. The sensitivity of sandeel is therefore considered to be medium.

Diadromous Species

333. Diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

334. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of most fish and shellfish IEFs (including herring) is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
335. For Nephrops and European lobster, the magnitude of the cumulative impact is deemed to be low and the sensitivity is considered to be medium. However, the significance of effect will not be greater than that assumed for the Proposed Development alone for the reasons outlined above.
336. For sandeel the magnitude of the cumulative effect is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

337. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

338. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning phase

339. There are no Tier 2 projects active in the Proposed Development decommissioning phase to consider for cumulative impacts based on current knowledge. Any programme changes resulting in decommissioning overlap with the Proposed Development are considered in paragraph 294.

Tier 3

Construction phase

Magnitude of impact

340. The only Tier 3 project which has been identified in the CEA with the potential to result in cumulative temporary habitat loss with the Proposed Development is the Cambois connection.
341. Values for the temporary habitat disturbance/loss associated with the construction of the Cambois connection are detailed in Table 9.35   Open ▸ . The values for the Cambois connection are based on information presented in the Scoping Report submitted in September 2022.

Table 9.35: Total Area and Component Parts of Temporary Habitat Loss/Disturbance of the Relevant Tier 3 Cumulative Impact Projects in the Construction Phase of the Proposed Development

342. Figure 9.11   Open ▸ shows that the Cambois connection extends far beyond the fish and shellfish ecology cumulative study area, therefore the majority of this disturbance will not spatially overlap with the Proposed Development. Up to 180 km of Cambois connection cables (i.e. four cables each up to 45 km in length) may however be installed within the Proposed Development array area which could result in up to 4.5 km2 of repeat disturbance within the Proposed Development array area previously impacted during the construction of the Proposed Development. The disturbance associated with the Cambois connection cable installation will however be highly localised (25 m width of potential disturbance) and so the potential for repeat disturbance is considered low and unlikely to lead to an increase in the magnitude than predicted for the Proposed Development alone.
343. The cumulative impact is predicted to be of regional spatial extent, medium term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

344. The sensitivity of fish and shellfish IEFs is as described in section 9.11, paragraphs 67 to 85.

Significance of the effect

Marine Species

345. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of most fish and shellfish IEFs (including herring) is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
346. For Nephrops and European lobster, the magnitude of the cumulative impact is deemed to be low and the sensitivity is considered to be medium. However, the significance of effect will not be greater than that assumed for the Proposed Development alone for the reasons outlined above.
347. For sandeel the magnitude of the cumulative effect is deemed to be low and the sensitivity is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

348. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

349. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Operation and maintenance phase

350. The only Tier 3 project which has been identified in the CEA with the potential to result in cumulative temporary habitat loss with the operation and maintenance of the Proposed Development is the Cambois connection. There are no specific values for the operation and maintenance phase of Cambois connection as the assessment of habitat loss which will occur during the operation and maintenance phase of the Proposed Development has not yet been completed, therefore values are unavailable. No quantification of Tier 3 cumulative impacts is possible at this stage and as a result, no assessment of the cumulative impacts of these projects can be made.

Decommissioning phase

351. There are no Tier 3 projects active in the Proposed Development decommissioning phase to consider for cumulative impacts based on current knowledge. Any programme changes resulting in decommissioning overlap with the Proposed Development are considered in paragraph 294.

Cumulative Increased suspended sediment concentrations and associated sediment deposition

352. Increased SSC and associated deposition may arise due to the seabed preparation, installation of the wind turbines and OSP/Offshore convertor substation platform foundations, the installation and/or maintenance of inter-array cables and the offshore export cables and associated decommissioning activities. Should the other projects cited take place concurrently with the Proposed Development construction or maintenance, there is potential for cumulative increased turbidity levels.

Tier 2

Construction phase

Magnitude of impact

353. The magnitude of the increase in SCC and associated deposition arising from the installation of wind turbines and OSP/Offshore convertor substation platform foundations, inter-array cables and offshore export cables during the construction phase, has been assessed as low for the Proposed Development alone, as described above in paragraph 113 et seq.
354. The construction phase of the Proposed Development coincides with the construction phases for Seagreen 1A Project. Construction of its 36 wind turbines will be completed by the end of 2025, which will lead to an overlap with the construction phase of the Proposed Development.
355. The Inch Cape Offshore Wind Farm will be in the final year of construction, with the installation of the offshore export cable being programmed for the period of overlap. The cable path is located to the east of the Proposed Development and should trenching activities be undertaken simultaneously the sediment plumes would not interact with those from the Proposed Development.
356. During the Proposed Development’s construction phase the Neart na Gaoithe Offshore Wind Farm and the Seagreen 1A Export Cable Corridor will be in operation and maintenance phase and maintenance activities may result in increased SCC, however these activities would be of limited spatial extent and frequency and unlikely to interact with sediment plumes from the Proposed Development.
357. The Eastern Link 1 Cable has Scottish landfall near Thorntonloch Beach, East Lothian. The landfall installation is proposed to be by HDD and although it is not yet confirmed which subsea trenching techniques will be used to install the cables, it is anticipated that mechanical ploughing or cutting and/or water jetting or Mass Flow Excavation (MFE) techniques will be used at different points along the route, in response to the seabed sediment conditions. Installation of the cables into soft sediments will seek to achieve a target burial depth of at least 1.5 m to 2 m and below the depth of mobile sediments depending on the nature of the seabed and potential hazards. Significant impacts of sediment plumes arising from cable laying activities are not anticipated. These installation parameters are similar to those for the Proposed Development offshore export cable installation and therefore the magnitude of the impact on the fish and shellfish receptors is anticipated to be low.
358. The Eastern Link 2 Cable runs to the east of the Proposed Development, skirting the FFBC MPA. For the extent of the overlap with the fish and shellfish ecology cumulative study area this is an offshore marine cable. The preferred subsea cable protection method is burial through trenching. It is not yet confirmed what subsea trenching equipment will be used to install the cables; however, it is anticipated similar methods to those proposed for Eastern Link 1 may be required, but this is dependent on the seabed conditions present within the offshore export cable corridor: It is anticipated that the magnitude of the impact on the fish and shellfish receptors would be low.
359. The CEA considers sea disposal of dredged material at the Eyemouth disposal site, located 31 km and 16.5 km from the Proposed Development array area and Proposed Development export cable corridor respectively. If offshore cable installation and dredge material dumping coincided, both resultant plumes would be advected on the tidal currents. The plumes would travel in parallel, and not towards one another, and are unlikely to interact in the event that offshore cables installation coincides with the use of the licensed sea disposal site (see volume 3, appendix 7.1).
360. The cumulative impact is predicted to be of local spatial extent, short term duration and intermittent and of high reversibility. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

361. The sensitivity of fish and shellfish IEFs is summarised below and is as described in section 9.11, paragraphs 120 to 128.

Marine Species

362. Based on the increase in sensitivity of herring eggs to the smothering effects of increased sediment deposition, herring is deemed to be of medium vulnerability, high recoverability and of regional importance, and therefore the sensitivity of this receptor is considered to be medium.
363. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of these IEFs is therefore considered to be low.

Diadromous Species

364. Diadromous fish species IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

365. For most fish and shellfish IEFs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
366. For herring, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

367. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

368. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning phase

369. As per the maximum design scenario, during the decommissioning phase all structures above the seabed would be removed. It is proposed to remove all export, inter-array and inter-connector cables and scour protection where possible and appropriate to do so. During decommissioning cables would be removed by similar processes as undertaken during installation therefore increases in suspended sediment concentrations would be of a similar form and magnitude. Following decommissioning, changes in suspended sediments concentration and sedimentation would return to baseline levels as it is anticipated that all structures above the seabed level will be completely removed and no further operation to disturb the seabed would be required. Therefore, refer to the assessment undertaken for the construction phase.

Tier 3

Construction phase

Magnitude of Impact

370. During the construction phase of the Proposed Development there is the potential for cumulative impacts with three Tier 3 cable installations. The Cambois connection is a 170 km offshore cable route extending southwards from the Proposed Development array area. Scoping indicates the project will consist of up to four cables installed in 2 m wide trenches up to 3 m in depth. Installation techniques may include jet trenching or cable ploughing, as ground conditions dictate. Site preparation will be required, such as boulder and sand wave clearance as part of the 36-month construction programme.
371. The cumulative impact is predicted to be of local spatial extent, short term duration, intermittent and of high reversibility. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

372. The sensitivity of fish and shellfish IEFs is as described in section 9.11, paragraphs 120 to 128.

Significance of the effect

Marine Species

373. For most fish and shellfish IEFs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
374. For herring, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

375. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

376. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Decommissioning phase

377. As per the maximum design scenario, during the decommissioning phase all structures above the seabed would be removed. It is proposed to remove all export, inter-array and inter-connector cables and scour protection where possible and appropriate to do so. Therefore, there is no contact with the seabed during decommissioning and subsequently no impact on the changes of SCC and sedimentation for cumulative impacts. During decommissioning cables would be removed by similar processes as undertaken during installation therefore increases in suspended sediment concentrations would be of a similar form and magnitude. Following decommissioning, changes in suspended sediments concentration and sedimentation would return to baseline levels as it is anticipated that all structures above the seabed level will be completely removed and no further operation to disturb the seabed would be required. Therefore, refer to the assessment undertaken for the construction phase.

Cumulative Injury and/or Disturbance to Fish and Shellfish From Underwater Noise and Vibration

Tier 2

Construction phase

Magnitude of impact

378. The Proposed Development, together with the projects and plans identified in Table 9.32   Open ▸ , may lead to injury and/or disturbance to fish and shellfish from underwater noise and vibration. The other projects and plans screened into the assessment are: Inch Cape Offshore Wind Farm and Seagreen 1A Project. Cumulative effects of underwater noise on fish and shellfish IEFs have the potential to occur as a result of the Proposed Development, together with the Inch Cape Offshore Wind Farm and Seagreen 1A.
379. These projects include similar construction activities as those described for the Proposed Development alone including piling of wind turbine and OSP/Offshore convertor substation platform foundations. As outlined in paragraph 187, all other noise sources including cable installation and foundation drilling will result in much lower noise levels than piling and will not represent a risk to injury or cause significant disturbance to fish and shellfish, such that they would result in cumulative effects with or from other projects. As such, the scope of this assessment focusses on piling noise, which represents the greatest risk to fish and shellfish receptors. The construction phases of Inch Cape Offshore Wind Farm and Seagreen 1A Project overlap the construction phase of the Proposed Development with construction for Inch Cape Offshore Wind Farm predicted to end in 2025 and Seagreen 1A Project predicted to end in 2025. However, during the time where construction phases overlap, there is the potential for cumulative effects. The construction figures for the Seagreen 1A Project in Table 9.36   Open ▸ accounts for piling associated with 36 wind turbines which make up Seagreen 1A Project.

Table 9.36:  Piling Parameters of the Relevant Cumulative Projects in the Construction Phase of the Proposed Development

380. Seagreen Alpha/Bravo Offshore Wind Farm Environmental Statement (Seagreen Wind Energy, 2012) reported that the maximum range for auditory injury for the most sensitive fish species (group 4 species) was 260 m. The Inch Cape Offshore Wind Farm Environmental Statement (Inch Cape Offshore Limited, 2018) reported injury ranges from piling activity on the most sensitive fish species (group 4 species) as follows:

• mortality and mortal injury: approximately 5 km2;
• recoverable injury: approximately 17 km2; and
• TTS: approximately 1,738 km2.
  381. Neither Inch Cape Offshore Wind Farm nor Seagreen Alpha/Bravo Offshore Wind Farm Environmental Statements predicted significant effects on fish and shellfish receptors. Any effects were predicted to be temporary and reversible following cessation of piling activities. Additionally, the injury ranges reported are likely to be conservative as soft start measures will be implemented as part of the Inch Cape Offshore Wind Farm and Seagreen 1A Project construction programmes, which will reduce the risk of injury considerably. Due to the minor overlap in construction phases of the Proposed Development and Inch Cape Offshore Wind Farm and Seagreen 1A Project, it is unlikely that cumulative effects will result in effects of greater significance than as assessed for the Proposed Development alone (see paragraph 152 et seq.).
  382. The cumulative impact is predicted to be of regional spatial extent, short term duration and intermittent and of high reversibility. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

383. The sensitivity of fish and shellfish IEFs is summarised below and is as described in section 9.11, paragraphs 159 to 196.

Marine Species

384. Based on the increase in sensitivity of herring eggs to underwater noise, herring is deemed to be of medium vulnerability, high recoverability and of regional importance, and therefore the sensitivity of this receptor is considered to be medium.
385. Sprat, cod and sandeel are deemed to be of medium vulnerability, high recoverability and regional to national importance. The sensitivity of the receptor is therefore, considered to be medium.
386. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of these IEFs is therefore considered to be low.

Diadromous Species

387. Diadromous fish species IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

388. For most fish and shellfish IEFs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
389. For herring, sprat, cod and sandeel, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

390. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

391. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Cumulative Long-term subtidal habitat loss

Tier 2

Construction and Operation and Maintenance Phase

Magnitude of impact

392. Long-term habitat loss will occur directly under all structures on the seabed, associated scour protection and cable protection, where this is required. Magnitude has been considered for the construction and operation and maintenance phases combined as the structures will be placed during construction and will be in place, with habitat loss continuing during the operation and maintenance phase. The installation of the projects outlined in Table 9.32   Open ▸ Table 9.32:              Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Cumulative Effects on Fish and Shellfish Ecology may lead to long-term subtidal habitat loss of up to 15,014,156 m2 within the fish and shellfish ecology CEA study area. Table 9.32:              Maximum Design Scenario Considered for Each Impact as Part of the Assessment of Likely Significant Cumulative Effects on Fish and Shellfish Ecology Table 9.32   Open ▸ shows all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, and Seagreen 1 and Seagreen 1A. The Seagreen 1A Export Cable Corridor Environmental Statement does not present a specific value for long term habitat loss, however, it is assumed that 20% of the cable length will require rock protection as a maximum design scenario.

The presence of offshore infrastructure at the Inch Cape Offshore Wind Farm may result in 2,470,000 m2 of long-term subtidal habitat loss (Inch Cape Offshore Limited, 2018). The presence of offshore infrastructure at Neart na Gaoithe Offshore Wind Farm may result in a total of 361,000 m2 of long-term habitat loss (Mainstream Renewable Power, 2019) The long term habitat loss values for the Seagreen 1A Project have been produced as part of the project specific assessment which was undertaken by RPS (further detail in paragraph 304). The presence of offshore infrastructure at Seagreen 1 may result in a total of 2,026,045 m2 of long-term habitat loss (Seagreen Wind Energy, 2012) and the Seagreen 1A Project may result in a total of 158,055 m2 of long-term habitat loss. The Seagreen 1A Export Cable Corridor Environmental Statement does not present a specific value for long term habitat loss, however, it is assumed that cable protection will be 6 m wide and may be required for up to 20% of the 110 km offshore export cable (Seagreen Wind Energy Ltd., 2021). Eastern Link 1’s environmental appraisal does not provide specific values for long term habitat loss except to state rock berm of a 7 m width will be installed. The cables installed as a result of Eastern Link 2 (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022) will result in 2,200,200 m2 of long term habitat loss. Additionally, only 24% of the 176 km Eastern Link 1 cable and only 18% of the 436 km Eastern Link 2 cables will be within the Proposed Development fish and shellfish study area therefore only a proportion of the overall impact will be cumulative. The details of the activities resulting in long-term subtidal habitat loss from each wind farm can be found in Table 9.37   Open ▸ . The total cumulative habitat loss would represent only a small proportion (i.e. <1%) of the fish and shellfish habitats within the area considered in this CEA.

393. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and not reversible during the construction and operation and maintenance phase of the relevant projects. It is predicted that the impact will affect the fish and shellfish receptors directly. The magnitude is therefore, considered to be low.

Table 9.37: Total Area and Component Parts of Long-Term Subtidal Habitat Loss of the Relevant Cumulative Projects in the Construction and Operation and Maintenance Phases of the Proposed Development

Sensitivity of the receptor

394. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 207 to 218.

Marine Species

395. Most fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low.
396. European lobster and Nephrops are deemed to be of high vulnerability, medium to high recoverability and of regional importance. The sensitivity of these fish and shellfish IEFs is therefore considered to be medium.
397. Sandeel are deemed to be of high vulnerability, high recoverability and of national importance. The sensitivity of these fish and shellfish receptor is therefore considered to be medium.
398. Herring are deemed to be of high vulnerability, medium recoverability and of regional importance. However, the sensitivity of herring to this impact is considered to be low, due to the limited suitable spawning sediments overlapping with the Proposed Development fish and shellfish ecology study area and the core herring spawning ground being located well outside the Proposed Development fish and shellfish ecology study area and project boundaries for other projects considered in the CEA.

Diadromous Species

399. Diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

400. For most fish and shellfish ecology IEFs (including herring) the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
401. For European lobster and Nephrops, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
402. For sandeel, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms

Diadromous Species

403. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

404. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Tier 3

Magnitude of impact

405. The only Tier 3 project which have been identified in the CEA with the potential to result in cumulative long-term habitat loss with the Proposed Development is the Cambois connection.
406. The values for the Cambois connection and the predicted extent of long term habitat loss associated with this project is presented in Table 9.38   Open ▸ and are based on information presented in the Cambois connection Scoping Report (SSER, 2022e) submitted in October 2022.
407. The installation of the Tier 2 and 3 projects may lead to cumulative long term subtidal habitat loss of up to 13,119,956 m2 or 0.16% of the fish and shellfish ecology CEA study area.
408. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Table 9.38: Total Area and Component Parts of Long Term Subtidal Habitat Loss of the Relevant Cumulative Projects in Tier 3 the Construction and Operation and Maintenance Operation and Maintenance Phases of the Proposed Development

Sensitivity of the receptor

409. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 207 to 218.

Significance of the effect

Marine Species

410. For most fish and shellfish ecology IEFs (including herring) the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
411. For European lobster and Nephrops, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.
412. For sandeel, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

413. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

414. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Cumulative Electromagnetic Fields from subsea electrical cabling

Tier 2

Operation and maintenance phase

Magnitude of impact

415. The operation and maintenance activities of the cumulative projects will overlap with the operation and maintenance phase of the Proposed Development and may impact fish and shellfish IEFs. Table 9.32   Open ▸ shows all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable Corridor, Eastern Link 1 and Eastern Link 2. As outlined in Table 9.15   Open ▸ , the Proposed Development may use a combination of HVAC and HVDC cables.
416. Inch Cape Offshore Wind Farm has the potential to produce EMF from 553 km of inter-array cables suitably buried and protected where burial is not possible. Additionally, the offshore export cables are approximately 83 km for each six cables, therefore the offshore export cables total length is 498 km. In combination with the Proposed Development this equates to 3,084 km of subsea cabling. This project will use a combination of HVAC and HVDC, however the design was not yet finalised in the environmental statement.
417. Neart na Gaoithe Offshore Wind Farm has the potential to produce EMF from 66 km of offshore export cables as well as 140 km of inter-array cables. In combination with the Proposed Development this equates to 2,506 km of subsea cabling. This project will use a combination of HVAC and HVDC, however the design was not yet finalised in the environmental statement.
418. Seagreen 1 and Seagreen 1A Project has the potential to produce EMF from 710 km of inter-array cables and 530 km of offshore export cables resulting in 1,240 km of subsea cabling. This arrangement included HVAC and HVDC however the design was not yet finalised in the environmental statement. Seagreen 1A Export Cable Corridor Environmental Statement does not provide details of the cable specifications used, but provides an approximate cable length of 110 km, which will have the potential to cause EMF effects
419. Eastern Link 1 has the potential to produce EMF from two 176 km HVDC cables resulting in up to 352 km of subsea cabling (National Grid Electricity Transmission and Scottish Power Transmission, 2022). Eastern Link 2 has the potential to produce EMF from two 436 HVDC cables resulting in up to 872 km of subsea cabling structures (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022).
420. The potential for cumulative impact of EMF on fish and shellfish IEFs during the Proposed Development operation and maintenance phase results from up to 6,112 km of subsea cabling, including the cables in the Proposed Development fish and shellfish ecology study area.
421. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and not reversible during the operation and maintenance phase (only at the decommissioning stage) of the relevant projects. It is predicted that the impact will affect the fish and shellfish IEFs directly. The magnitude is therefore, considered to be low. This can be concluded as EMF effects are confined to the close vicinity of cables. While the sediments in which cables are buried will not reduce the strength of EMF, the burial of cables does increase the distance between cables and fish and shellfish IEFs, with greater attenuation of EMFs with greater distance from the cable, thereby potentially reducing the effect of EMFs on those IEFs (see paragraph 233 et seq.).

Table 9.39: Total Cable Length of the Relevant Cumulative Projects in the Operation and Maintenance Phases of the Proposed Development (Seagreen 1A Export Cable Corridor not Included in Cumulative Length)

Sensitivity of the receptor

422. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 241 to 254.

Marine Species

423. Marine fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low to medium vulnerability, high recoverability and local to national importance. The sensitivity of the receptor is therefore, considered to be low (most fish and shellfish IEFs) to medium (decapod crustaceans and elasmobranchs).

Diadromous Species

424. Diadromous fish IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of the receptor is therefore, considered to be low.

Significance of the effect

Marine Species

425. For most fish and shellfish ecology IEFs (including herring) the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
426. For European lobster and Nephrops edible crab and elasmobranchs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

427. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

428. No additional fish and shellfish ecology mitigation is considered necessary as the predicted effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Tier 3

Operation and Maintenance Phase

Magnitude of impact

429. The only Tier 3 project which have been identified in the CEA with the potential to result in cumulative EMF effects from subsea electrical cabling within the Proposed Development is the Cambois connection. The Cambois connection includes up to 680 km of cable therefore combining this with tier 2 projects and the Proposed Development would lead to a cumulative length of 6,792 km.
430. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and not reversible during the operation and maintenance phase (only at the decommissioning stage) of the relevant projects. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

431. The sensitivity of fish and shellfish IEFs is low as described in section 9.11, paragraphs 241 to 254.

Significance of the effect

Marine Species

432. For most fish and shellfish ecology IEFs (including herring) the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.
433. For European lobster and Nephrops edible crab and elasmobranchs, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the receptor is considered to be medium. The cumulative effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

Diadromous Species

434. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

435. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Cumulative Colonisation of foundations, scour protection and cable protection

Tier 2

Operation and maintenance phase

Magnitude of impact

436. The introduction of hard substrate into areas of predominantly soft sediments has the potential to alter community composition and biodiversity. This impact is only relevant to the operation and maintenance phase as it takes time for colonisation to establish post construction. The presence of the projects listed in Table 9.32   Open ▸ has the potential to lead to cumulative impacts arising from the colonisation of up to 17,513,271 m2 of hard structures from wind turbines, OSP/Offshore convertor substation platforms, meteorological masts, cable protection, and cable crossings. Table 9.32   Open ▸ lists all projects/plans/activities considered in the Tier 2 assessment which are Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, and Seagreen 1, Seagreen 1A Project Seagreen 1A Export Cable Corridor, Eastern Link 1 and Eastern Link 2. There are no values for long-term habitat loss provided in the Environmental Statement for Seagreen 1A Export Cable Corridor however 20% of the 110 km may require cable protection up to 6 m wide (Seagreen Wind Energy Ltd., 2021).
437. Inch Cape Offshore Wind Farm will contribute to cumulative impacts from the colonisation of hard structures through the presence of wind turbines, substations, and meteorological masts, as well as cable protection for the inter-array and offshore export cables. In the Inch Cape Environmental Statement it is stated that the amount of new hard substrate resulting from Inch Cape Offshore Wind Farm is equivalent to the amount of long-term habitat loss (Inch Cape Offshore Limited, 2018) which is described in Table 9.37   Open ▸ and equates to 2,470,000 m2 of new hard structures (Inch Cape Offshore Limited, 2018).
438. At the Neart na Gaoithe Offshore Wind Farm, colonisation of hard substrate is predicted to result from the presence of gravity base foundations for the wind turbine foundations, substation foundations, scour protection and cable protection. The amount of new hard substrate equates to 460,000 m2 of new hard structures as shown in Table 9.40   Open ▸ (Mainstream Renewable Power, 2019).
439. The Seagreen 1 Offshore Wind Farm maximum design scenario for the colonisation of hard structures, as stated in the Environmental Statement (Seagreen Wind Energy, 2012), show that the area available for colonisation is expected to be approximately the same area as is considered for as for long-term habitat loss, the components of which are described in Table 9.37   Open ▸ and equates to 2,026,045 m2 of new hard structure (Seagreen Wind Energy, 2012).
440. The Seagreen 1A Project hard substrate values have been calculated through a project specific assessment by RPS (further detail in paragraph 304). This assessment showed that the area available for colonisation is expected to be approximately the same area as is considered for long term habitat loss, the components of which are described in Table 9.40   Open ▸ and equates to 158,055 m2 of new hard structure.
441. The hard substrate installed for Eastern Link 1 includes rock berm with a maximum width of 7 m, no further values regarding hard substrate have been provided (National Grid Electricity Transmission and Scottish Power Transmission, 2022).
442. The hard substrate installed for Eastern Link 2 includes rock berms up to 138 km, six pipeline crossings, 18 cable crossings and rock protection at the landfall. The amount of new hard substrate available is equivalent to the amount of long term habitat loss which is described in Table 9.40   Open ▸ and equates to 2,200,200 m2 of new hard structures (National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc, 2022).
443. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Table 9.40: Total Area and Component Parts of Introduced Hard Substrate of the Relevant Cumulative Projects in the Operation and Maintenance Phase of the Proposed Development

Sensitivity of the receptor

444. The sensitivity of fish and shellfish IEFs is summarised below, and is as described in section 9.11, paragraphs 263 to 279.

Marine Species

445. Marine fish and shellfish ecology IEFs in the Proposed Development fish and shellfish ecology study area are deemed to be of low vulnerability, and local to national importance (recoverability is not relevant to this impact during the operation maintenance phase). The sensitivity of the receptor is therefore, considered to be low.

Diadromous Species

446. Most diadromous fish species are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of these IEFs is therefore, considered to be low.
447. Atlantic salmon and sea lamprey are deemed to be of low vulnerability, high recoverability and national to international importance. The sensitivity of these IEFs is therefore, considered to be low.
448. Sea trout are deemed to be of medium vulnerability, high recoverability and national importance. The sensitivity of this IEF is therefore, considered to be low.

Significance of the effect

Marine Species

449. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the IEFs is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

450. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of these IEFs is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

451. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

Tier 3

Operation and maintenance phase

Magnitude

452. The only Tier 3 project which have been identified in the CEA with the potential to result in cumulative colonisation of foundations, scour protection and cable protection with the Proposed Development is the Cambois connection.
453. The Cambois connection has the potential to create 306,000 m2 of new hard habitat associated with rock/mattress cable protection which represents protection covering 15% the total length the four offshore export cables (See Table 9.38   Open ▸ ), therefore it is likely that only a proportion of the cable protection will occupy the fish and shellfish ecology CEA study area, or potentially none of it. The cable protection represents a change in seabed type, the effects of which are described in paragraph 263 et seq., however as the cable protection does not extend into the water column the opportunity for colonisation by some species is reduced. The presence of the Tier 2 and 3 projects has the potential to lead to cumulative impacts arising from the colonisation of up to 15,313,071 m2 of hard structures.
454. The cumulative impact is predicted to be of local spatial extent, long term duration, continuous and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.

Sensitivity of the receptor

455. The sensitivity of fish and shellfish IEFs is low as described in section 9.11, paragraphs 263 to 279.

Significance of the effect

Marine Species

456. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of the IEFs is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Diadromous Species

457. Overall, the magnitude of the cumulative effect is deemed to be low and the sensitivity of these IEFs is considered to be low. The cumulative effect will, therefore, be of negligible to minor adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

458. No additional fish and shellfish ecology mitigation is considered necessary as the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 9.10) is not significant in EIA terms.

9.12.4.              Proposed Monitoring

459. Proposed monitoring measures for cumulative effects are the same as outlined in Table 9.30   Open ▸ .

9.13.   Transboundary Effects

9.13. Transboundary Effects

460. A screening of transboundary impacts has been carried out and has identified that there was no likely significant transboundary effects with regard to fish and shellfish ecology from the Proposed Development upon the interests of other European Economic Area (EEA) States. This was due to the relatively limited scale of effect and/or temporary nature of the impacts on fish and shellfish which would not result in effects occurring in other countries.

9.14.   Inter-Related Effects (And Ecosystem Assessment)

9.14. Inter-Related Effects (And Ecosystem Assessment)

461. A description of the likely inter-related effects arising from the Proposed Development on fish and shellfish ecology is provided in volume 2, chapter 20 of the Offshore EIA Report.
462. For fish and shellfish ecology, the following potential impacts have been considered within the inter-related assessment:

• temporary and long-term subtidal habitat loss/disturbance;
• increased SSC and associated sediment deposition;
• EMFs from subsea electrical cabling;
• injury and/or disturbance to fish and shellfish from underwater noise and vibration; and
• colonisation of foundations, scour protection and cable protection.
  463. Table 9.41   Open ▸ lists the inter-related effects (project lifetime effects) that are predicted to arise during the construction, operation and maintenance phase, and decommissioning of the Proposed Development and also the inter-related effects (receptor-led effects) that are predicted to arise for marine mammal, offshore ornithology and commercial fisheries receptors.
  464. As noted above, effects on fish and shellfish ecology also have the potential to have secondary effects on other receptors and these effects are fully considered in the topic-specific chapters. These receptors and effects are:
• marine mammals:

–      changes in the fish and shellfish community resulting from impacts during construction, operation and maintenance, and decommissioning may lead to loss of prey resources for marine mammals resulting in effects of imperceptible significance (see volume 2, chapter 10);

• offshore ornithology:

–      One key stressor has been identified for offshore and intertidal ornithology. The assessment considers the overall effects on foraging seabirds from potential changes in prey communities that could be caused by disturbance, habitat loss, SSC, and therefore, in this respect, has taken an ecosystem-based approach. The assessment of effects, however, demonstrated that due to the high mobility of foraging seabirds and their ability to exploit different prey species, and the small scale of potential changes in context of wider available habitat, the changes to fish prey communities are unlikely to have a significant effect on foraging seabirds (see volume 2, chapter 11); and

• commercial fisheries:

–      changes in the fish and shellfish community resulting from impacts during construction, operation and maintenance, and decommissioning may affect commercial fisheries receptors by effects on target species, however as noted in this chapter there are negligible or minor  effects on fish and shellfish receptors therefore negligible or minor  effects are predicted for commercial fisheries (see volume 2, chapter 12), which are not significant in EIA terms.

Table 9.41: Summary of Likely Significant Inter-Related Effects on the Environment for Fish and Shellfish Ecology from Individual Effects Occurring across the Construction, Operation and Maintenance and Decommissioning Phases of the Proposed Development and from Multiple Effects Interacting Across all Phases (Receptor-led Effects)

9.15.   Summary of Impacts, Mitigation Measures, Likely Significant Effects and Monitoring

9.15. Summary of Impacts, Mitigation Measures, Likely Significant Effects and Monitoring

465. Information on fish and shellfish ecology within the Proposed Development fish and shellfish ecology study area and the Proposed Development northern North Sea fish and shellfish ecology study area was collected through desktop review, site specific surveys, and consultation. These are summarised in Table 9.8   Open ▸ to Table 9.10   Open ▸ . The baseline characterisation was used to inform the assessment of the fish and shellfish assemblage present within the vicinity of the Proposed Development fish and shellfish ecology study area. Full details of the baseline characterisation are provided in volume 3, appendix 9.1.
466. Table 9.42   Open ▸ presents a summary of the potential impacts, mitigation measures and the conclusion of likely significant effects in respect to fish and shellfish ecology in EIA terms. The impacts assessed include: temporary subtidal habitat loss/disturbance, increased SSC and associated sediment deposition, injury and/or disturbance to fish and shellfish from underwater noise and vibration, long-term subtidal habitat loss, EMFs from subsea electrical cabling, and colonisation of foundations, scour protection and cable protection. Overall, it is concluded there will be negligible adverse significant effects arising from the Proposed Development during the construction, operation and maintenance or decommissioning phases.
467. Table 9.43   Open ▸ presents a summary of the potential cumulative impacts, mitigation measures and the conclusion of likely significant cumulative effects on fish and shellfish ecology in EIA terms. The cumulative effects assessed include: temporary subtidal habitat loss/disturbance, increased SSC and associated sediment deposition, injury and/or disturbance to fish and shellfish from underwater noise and vibration, long-term subtidal habitat loss, EMFs from subsea electrical cabling, and colonisation of foundations, scour protection and cable protection. Overall, it is concluded that there will be negligible adverse significant cumulative effects from the Proposed Development alongside other projects/plans.
468. As noted in section 9.9.3, an assessment of the likely significant effects in EIA terms on the relevant features of sites that comprise part of the UK National Site Network or Natura 2000 network (i.e. European Sites) has been made in this chapter (in sections 0 and 9.12), The assessment of the potential impacts on the site itself are deferred to the RIAA (SSER, 2022c) for the Proposed Development. The RIAA concluded that no adverse effect on integrity was predicted to occur on any of the sites designated for Annex I habitats below MHWS, specifically:

• River Tay SAC;
• River Tweed SAC;
• Tweed Estuary SAC;
• River Teith SAC;
• River South Esk SAC; and
• River Dee SAC.
  469. An assessment on the individual qualifying interest features of the sites relevant to fish and shellfish ecology has also been undertaken in this chapter.
  470. No likely significant transboundary effects have been identified in regard to effects of the Proposed Development.
  471. As noted in section 9.9.3, the full assessment of the potential impacts on the sites that comprise part of the UK National Site Network or Natura 2000 network (i.e. European Sites) has been deferred to the RIAA (SSER, 2022c) for the Proposed Development. An assessment on the individual qualifying interest feature(s) of these sites (e.g. Annex II species such as Atlantic salmon ) is considered in this chapter (section 9.11 and 9.12.3), as summarised above. The RIAA concluded that no adverse effect on integrity was predicted to occur on any of the sites designated for fish and shellfish receptors, specifically.

Table 9.42: Summary of Likely Significant Environmental Effects, Mitigation and Monitoring

Table 9.43: Summary of Likely Significant Cumulative Environment Effects, Mitigation and Monitoring

9.16.   References

9.16. References

Agnalt, A.L., Kristiansen, T.S. and Jorstad, K.E. (2007). Growth, Reproductive Cycle and Movement of Berried European Lobsters (Homarus gammarus) in a Local Stock off Southwestern Norway. ICES Journal of Marine Sciences 64:288-297.

Aires, C., González-Irusta, J.M., Watret, R. (2014) Updating Fisheries Sensitivity Maps in British Waters. Scottish Marine and Freshwater Science Vol 5 No 10. Edinburgh: Scottish Government, 88pp. DOI: 10.7489/1555-1

Andersson, M. and Öhman, M. (2010). Fish and sessile assemblages associated with wind-turbine constructions in the Baltic Sea. Marine and Freshwater Research 61, 642-650.

Andersson, M. H. (2011). Offshore Wind Farms - Ecological Effects of Noise and Habitat Alteration on Fish. PhD Thesis, Department of Zoology, Stockholm University.

Andersson, M. H. (2011) Offshore Wind Farms - Ecological Effects of Noise and Habitat Alteration on Fish. PhD Thesis, Department of Zoology, Stockholm University.

Andersson, M. H., Berggren, B., Wilhelmsson, D., and Öhman, M. C. (2009) Epibenthic Colonization of Concrete and Steel Pilings in a Cold-Temperate Embayment: A Field Experiment. Helgoland Marine Research, 63, pp. 249–260.

Appleby, J.A. and Scarratt (1989) Physical effects of suspended solids on marine and estuarine fish and shellfish, with special reference to ocean dumping: a literature review. Canadian Technical Report of Fisheries and Aquatic Sciences No. 1681. October 1989.

Armstrong, J.D., D.C. Hunter, R.J. Fryer, P. Rycroft, and J.E. Orpwood. (2015) Behavioural responses of Atlantic salmon to mains frequency magnetic fields. Scottish Marine and Freshwater Science 6:9.

Atema, J. and Cobb, J. S. (1980) Social behaviour in the biology and management of lobsters 409–450.

Bergström, L., Sundqvist, F., Bergström, U. (2013) Effects of an offshore wind farm on temporal and spatial patterns in the demersal fish community. Marine Ecology Progress Series 485, 11pp.

BioConsult (2006). Hydroacoustic Monitoring of Fish Communities at Offshore Wind Farms, Horns Rev Offshore Wind Farm, Annual Report 2005.

Birklund, J. and Wijsman, J. W. M. (2005). Aggregate Extraction: A Review on the Effects on Ecological Functions. Report Z3297/10 SAWDPIT Fith Framework Project no EVK3-CT-2001-00056. Available at: https://repository.tudelft.nl/islandora/object/uuid%3A11ee2c93-2dfd-429e-acd4-a079a0fa2552 Accessed on: 18/01/2022

Bodznick, D. and Northcutt, R.G. (1981) Electroreception in Lampreys: Evidence that the Earliest Vertebrates were Electroreceptive. Science, 212, 465-467.

Bodznick, D. and Preston, D.G. (1983) Physiological Characterization of Electroreceptors in the Lampreys. Ichthyomyzon uniscuspis and Petromyzon marinus. Journal of Comparative Physiology 152, 209-217.

Bohnsack, J. A. (1989) Are High Densities of Fishes at Artificial Reefs the Result of Habitat Limitation or Behavioural Preference? B. Mar. Sci., 44(2), pp. 631-645.

Bouma, S. and Lengkeek, W. (2008) Benthic communities on hard substrates within the first Dutch offshore wind farm (OWEZ). Algae 2011.

BOWind (2008) Barrow Offshore Wind Farm Post Construction Monitoring Report. First annual report. 15 January 2008, 60pp.

BOWL (2021a) Beatrice Offshore Wind Farm Post-Construction Sandeel Survey–Technical Report

BOWL (2021b) Beatrice Offshore Wind Farm Post-Construction Cod Spawning Survey – Technical Report

Brand, A.R. & Roberts, D., (1973) The cardiac responses of the scallop Pecten maximus (L.) to respiratory stress. Journal of Experimental Marine Biology and Ecology, 13, 29-43.

Campbell, A., and Stasko, A. B. (1985) Movements of tagged American lobster, Homarus americanus, off southwestern Nova Scotia. Canadian Journal of Fisheries and Aquatic Sciences, 42: 229–238.

Cefas (2009) Strategic Review of Offshore Wind Farm Monitoring Data Associated with FEPA Licence Conditions. Project ME1117. July 2009.

Christian, J.R., A. Mathieu, D.H. Thomson, D. White, R.A. Buchanan (2013). Effect of Seismic Energy on Snow Crab (Chionoecetes opilio). Prepared for National Energy Board, Calgary, AB., File No. CAL-1-00364 (2003), p. 50

Chung-Davidson., Y., Bryan, M.B., Teeter, J., Bedore, C.N., and Li, W. (2008) Neuroendocrine and Behavioural Responses to Weak Electric Fields in Adult Sea Lampreys (Petromyzon marinus). Hormones and Behaviour, 54(1), 34-40.

CIEEM (2019) Guidelines for Ecological Impact Assessment in the UK and Ireland. Terrestrial, Freshwater, Coastal and Marine, September 2018, Version 1.1 – Updated September 2019.

CMACS (Centre for Marine and coastal studies). (2003) A Baseline Assessment of Electromagnetic fields Generated by Offshore Wind farm Cables. Report No. COWRIE EMF-01-2002, 66. Centre for Marine and Coastal Studies, Birkenhead, UK.

Comeau, M., and Savoie, F. (2002) Movement of American lobster (Homarus americanus) in the southwestern Gulf of St Lawrence. Fishery Bulletin US, 100: 181–192.

Coull, K.A., Johnstone, R, and Rogers, S.I. (1998) Fisheries Sensitivity Maps in British Waters. UKOOA Ltd: Aberdeen.

Cresci, A., Allan, B.J.M., Shema, S.D., Skiftesvik, A.B., Browman, H.I., (2020). Orientation behaviour and swimming speed of Atlantic herring larvae (Clupea harengus) in situ and in laboratory exposures to rotated artificial magnetic fields. J. Exp. Mar. Biol.Ecol. 526, 151358 https://doi.org/10.1016/j.jembe.2020.151358.

Cresci, A., Perrichon, P., Durif, C.M., Sørhus, E., Johnsen, E., Bjelland, R., Larsen, T., Skiftesvik, A.B. and Browman, H.I., (2022). Magnetic fields generated by the DC cables of offshore wind farms have no effect on spatial distribution or swimming behaviour of lesser sandeel larvae (Ammodytes marinus). Marine Environmental Research, 176, p.105609.

CSA (2019). Evaluation of Potential EMF Effects on Fish Species of Commercial or Recreational Fishing Importance in Southern New England. U.S. Dept. of the Interior, Bureau of Ocean Energy Management, Headquarters, Sterling, VA. OCS Study BOEM 2019-049. 59 pp.

Danish Energy Agency (2013) Danish Offshore Wind. Key Environmental Issues - a Follow-up. The Environmental Group: The Danish Energy Agency, The Danish Nature Agency, DONG Energy and Vattenfall.

De Soto. A., N. Delorme, J. Atkins, S. Howard, J. Williams, M. Johnson, (2013). Anthropogenic noise causes body malformations and delays development in marine larvae. Sci. Reproduction, 3 (2013), p. 2831.

Desprez, M. (2000) Physical and biological impact of marine aggregate extraction along the French coast of the eastern English Channel: short and long-term post-dredging restoration. ICES Journal of Marine Science 57, 1428-1438.

DFO, 2004. Potential impacts of seismic energy on snow crab. DFO Can Sci Advis Sec. Habitat Status Report 2004/003, p. 2.

Edmonds, N.J., C.J. Firmin, D Goldsmith, R C. Faulkner, DT. Wood, (2016). A review of crustacean sensitivity to high amplitude underwater noise: Data needs for effective risk assessment in relation to UK commercial species. Marine Pollution Bulletin, Volume 108, Issues 1–2, 2016, Pages 5-11.

EGS (2011) Lynn and Inner Dowsing Offshore Wind Farms Post-Construction Survey Works Phase 2 – Benthic Ecology Survey Centrica Contract No. CREL/C/400012, Final Report. 184pp.

Ellis, J.R., Milligan, S.P., Readdy, L., Taylor, N. and Brown, M.J. (2012) Spawning and nursery grounds of selected fish species in UK waters. Scientific Series Technical Report. Cefas Lowestoft, 147: 56 pp

EMU (2004) Subsea Cable Decommissioning – A Limited Environmental Appraisal. Report commissioned by British Telecommunications plc, Cable and Wireless and AT&T, Report no. 04/J/01/06/0648/0415, available from UKCPC.

EMU (2008a) Barrow Offshore Wind Farm Monopile Ecological Survey. Report No 08/J/1/03/1321/0825. Report prepared on behalf of Narrow Offshore Wind Ltd. December 2008.

EMU (2008b) Kentish Flats Offshore Wind Farm Turbine Foundation Faunal Colonisation Diving Survey. Report No 08/J/1/03/1034/0839. Prepared on behalf of Kentish Flats Ltd. November 2008.

Filiciotto, F. Vazzana, M. Celi,M. Maccarrone, V. Ceraulo, M. Buffa, G. & Arizza, V. de Vincenzi, G. Rosario, G. Mazzola, S. Buscaino, G. (2016). Underwater noise from boats: Measurement of its influence on the behaviour and biochemistry of the common prawn (Palaemon serratus, Pennant 1777). Journal of Experimental Marine Biology and Ecology. 478. 10.1016/j.jembe.2016.01.014.

Gill, A. B. and Bartlett, M. (2010). Literature Review on the Potential Effects of Electromagnetic Fields and Subsea Noise from Marine Renewable Energy Developments on Atlantic Salmon, Sea Trout and European Eel. Scottish Natural Heritage, Commissioned Report No. 401. (Sutton and Boyd, 2009).

Gill, A. B., Gloyne-Phillips, I., Neal, K. J. and Kimber, J. A. (2005) The Potential Effects of Electromagnetic Fields Generated by Sub-Sea Power Cables Associated with Offshore Wind Farm Developments on Electrically and Magnetically Sensitive Marine Organisms – A Review. COWRIE 1.5 Electromagnetic Fields Review.

Gill, A.B. and Taylor. H. (2001) The Potential of Electromagnetic Fields Generated by Cabling between Offshore Wind Turbines upon Elasmobranch Fishes. Report for the Countryside Council for Wales (CCW Science report No. 488) 60pp.

Gill, A.B., Huang, Y., Gloyne-Philips, I., Metcalfe, J., Quayle, V., Spencer, J. and Wearmouth, V. (2009) COWRIE 2.0 Electromagnetic Fields (EMF) Phase 2: EMF-Sensitive Fish Response to EM Emissions from Sub-Sea Electricity Cables of the Type used by the Offshore Renewable Energy Industry. COWRIE-EMF-1-06.

Gardiner, R., Main, R., Kynoch, R., Gilbey, J., and Davies, I., (2018a). A needle in the haystack? Seeking salmon smolt migration routes off the Scottish east coast using surface trawling and genetic assignment. Poster presentation to the MASTS Annual Science Meeting 31 October – 2 November 2018.

Gardiner, R., Main, R., Davies, I., Kynoch, R., Gilbey, J., Adams, C., and Newton M. (2018b). Recent investigations into the marine migration of salmon smolts in the context of marine renewable development. Conference Presentation. Environmental Interactions of Marine Renewables (EIMR) Conference, Kirkwall, 24-26 April 2018.

Harding, H., Bruintjes, R., Radford, A. N., and Simpson, S. D., (2016). Measurement of Hearing in the Atlantic salmon (Salmo salar) using Auditory Evoked Potentials, and effects of Pile Driving Playback on salmon Behaviour and Physiology. Marine Scotland Science; Scottish Marine and Freshwater Science, 7: 46–47.Hawkins, A. (2009) The impact of pile driving upon fish. Proc. Inst. Acoustics, vol.31. pt.1, pp. 72-79.

Harsanyi, P., Scott, K., Easton, B.A., de la Cruz Ortiz, G., Chapman, E.C., Piper, A.J., Rochas, C.M. and Lyndon, A.R., (2022) The Effects of Anthropogenic Electromagnetic Fields (EMF) on the Early Development of Two Commercially Important Crustaceans, European Lobster, Homarus gammarus (L.) and Edible Crab, Cancer pagurus (L.). Journal of Marine Science and Engineering, 10(5), p.564.

Hawkins, A. D. and Popper, A. N. (2016) A sound approach to assessing the impact of underwater noise on marine fishes and invertebrates. ICES Journal of Marine Science, 74 (3): 635-651.

Hawkins, A. D., Roberts L., and S. Cheesman (2014a) Responses of free-living coastal pelagic fish to impulsive sounds, J. Acoust. Soc. Am., 135, PP3101-3116

Holland, G. J., Greenstreet, S. P. R., Gibb, I. M., Fraser, H. M. and Robertson, M. R., (2005) Identifying Sandeel Ammodytes marinus Sediment Habitat Preferences in the Marine Environment. Mar. Ecol. Prog. Ser., 303, pp. 269-282.

Howell, T.R.W & Fraser, D.I., (1984) Observations on the dispersal and mortality of the scallop Pecten maximus (L.). ICES Council Meeting Papers, K: 35.

Huang, Y. (2005) Electromagnetic Simulations of 135-kV Three phase Submarine Power Cables. Centre for Marine and Coastal Studies, Ltd. Prepared for Sweden Offshore.

Hughes, S.L., Hindson, J., Berx, B., Gallego, A. and Turrell, W.R. (2018) Scottish Ocean Climate Status Report 2016. Scottish Marine and Freshwater Science Vol 9 No 4, 167pp. DOI: 10.7489/12086-1

Hume, J. (2017) A review of the geographic distribution, status and conservation of Scotland’s lampreys. The Glasgow Naturalist. Volume 26, Part 4 Available at: https://www.glasgownaturalhistory.org.uk/gn26_4/Hume_lampreys_Scotland.pdf. Accessed on: 09/01/2022

Hutchison, Z.L., P. Sigray, H. He, A.B. Gill, J. King, and C. Gibson. (2018) Electromagnetic Field (EMF) Impacts on Elasmobranch (shark, rays, and skates) and American Lobster Movement and Migration from Direct Current Cables. Sterling (VA): U.S. Department of the Interior, Bureau of Ocean Energy Management. OCS Study BOEM 2018-003.

Hvidt, C. B., Bech, M., and Klaustrup, M. (2003) Monitoring programme-status report 2003. Fish at the cable trace. Nysted offshore wind farm at Rødsand. Bioconsult.

ICES. (2006). Herring, Clupea harengus. Available at: https://www.ices.dk/about-ICES/projects/EU-RFP/EU%20Repository/ICES%20FIshMap/ICES%20FishMap%20species%20factsheet-herring.pdf. Accessed on: 10/02/2022Inch Cape Offshore Limited (2018). Offshore Environmental Statement: Chapter 12 Benthic Ecology. Available at: tethys.pnnl.gov/sites/default/files/publications/inch2011.pdf Accessed on: 23 December 2021.

Inger, R., Attril, M.J., Bearhop, S., Broderick, A.C., Grecian, W.J., Hodgson, D.J., Mills, C., Sheehan, E., Votier, S.C., Witt, M.J., and Godley, B.J. (2009) Marine Renewable Energy: Potential Benefits to Biodiversity? An Urgent Call for Research. Journal of Applied Ecology, 46, 1145-1153.

Jensen, H., Kristensen, P.S., Hoffmann, E. (2004) Sandeels in the wind farm area at Horns Reef. Report to ELSAM, August 2004. Danish Institute for Fisheries Research, Charlottenlund.

Jensen, H., Rindorf, A., Wright, P. J., and Mosegaard, H. (2011). Inferring the location and scale of mixing between habitat areas of lesser sandeel through information from the fishery. – ICES Journal of Marine Science, 68: 43–51.Jensen, H., Rindorf, A., Wright, P.J. and Mosegaard, H. (2010) Inferring the location and scale of mixing between habitat areas of lesser sandeel through information from the fishery. ICES Journal of Marine Science, 68 (1), p42.

Kavet, R., M.T. Wyman, and A.P. Klimley. (2016). Modelling magnetic fields from a dc power cable buried beneath San Francisco bay based on empirical measurements. PLoS One 11(2):e0148543.

Kempster, R.M., N.S. Hart, and S.P. Collin. (2013). Survival of the Stillest: Predator Avoidance in Shark Embryos. PLoS ONE 8(1):e52551.

Knutsen, J., Knutsen, H., Gjøsæter, J. & Jonsson, B. (2001). Food of anadromous brown trout at sea. Journal of Fish Biology. 59. 533 - 543. 10.1111/j.1095-8649.2001.tb02359.x.

Krone, R. Gutowa, L. Joschko, TJ. Schröder, A. (2013) Epifauna dynamics at an offshore foundation Implications of future wind power farming in the North Sea. Marine Environmental Research, 85, 1-12.

Lagardère J.-P. and M. Spérandio, (1981). Lagardère, Influence du niveau sonore de bruit ambiant sur la croissance de la crevett Crangon crangon. Resultats préliminaires Aquaculture, 24 (1981), pp. 77-90.

Langhamer, O., Holand, H. and Rosenqvist, G. (2016) Effects of an Offshore Wind Farm (OWF) on the common shore crab carcinus maenas: Tagging pilot experiments in the Lillgrund Offshore Wind Farm (Sweden). PLoS One 11, 1–17.

Langton R, Boulcott P, Wright PJ (2021) A verified distribution model for the lesser sandeel Ammodytes marinus. Mar Ecol Prog Ser 667:145-159. https://doi.org/10.3354/meps13693.Lee, P. H. and Weis, J. S. (1980) Effects of magnetic fields on regeneration in fiddler crabs. Biol. Bull. 159, 681–691.

Lindeboom, H.J., Kouwenhoven, H.J., Bergman, M.J.N., Bouma, S., Brasseur, S., Daan, R., Fijn, R.C. de Haan, D., Dirksen, S., van Hal, R., Hille Ris Lambers, R., ter Hofstede, R., Krijgsveld, K.L., Leopold, M. and Scheidat, M. (2011) Short-term ecological effects of an offshore wind farm in the Dutch coastal zone; a compilation. Environmental Research Letters, 6, 035101, 13pp.

Linley, E.A.S., Wilding, T.A., Black, K., Hawkins, A.J.S. and Mangi S. (2007) Review of the Reef Effects of Offshore Wind Farm Structures and their Potential for Enhancement and Mitigation. Report from PML Applications Ltd and the Scottish Association for Marine Science to the Department for Business, Enterprise and Regulatory Reform (BERR), Contract No: RFCA/005/0029P.

Lohmann, K.J., N.D. Pentcheff, G.A. Nevitt, G.D. Stetten, R.K. Zimmer-Faust, H.E. Jarrard, and L.C. Boles. (1995). Magnetic orientation of spiny lobsters in the ocean: experiments with undersea coil systems. Journal of Experimental Biology 198:2,041-2,048.

Love, M.S., M.M. Nishimoto, S. Clark, and A.S. Bull. (2016). Renewable Energy in situ Power Cable Observation. U.S. Department of the Interior, Bureau of Ocean Energy Management, Pacific OCS Region, Camarillo, CA. OCS Study 2016-008. 86 pp.

Marine Scotland (2011) Scotland's Marine Atlas: Information for The National Marine Plan. Available at: https://www.gov.scot/publications/scotlands-marine-atlas-information-national-marine-plan/pages/9/ Accessed on: 13/12/2021

Marine Scotland (2019) Sandeel Surveys in the East Coast. Available at: https://blogs.gov.scot/marine-scotland/2019/12/06/sandeel-surveys-in-the-east-coast/ Accessed on: 04/02/2022Mainstream Renewable Power (2019). Neart Na Gaoithe Offshore Wind Farm Environmental Statement: Chapter 14 Benthic Ecology. Available at: marine.gov.scot/sites/default/files/chapter_14_-_benthic_ecology.pdf. Accessed on: 23 December 2021

Marine Scotland (2018). Marine Licence - Maintenance Dredging and Sea Disposal - Eyemouth Harbour - 06746. Available at: marine.gov.scot/ml/marine-licence-maintenance-dredging-and-sea-disposal-eyemouth-harbour-06746. Accessed on: 23 December 2021.

MarLIN (2021) Marine Evidence based Sensitivity Assessment (MarESA) Available at: MarLIN - The Marine Life Information Network - Marine Evidence based Sensitivity Assessment (MarESA). Accessed on: 08/01/2022

MarLIN (2022) The Marine Life Information Network - Great scallop (Pecten maximus) Available at: https://www.marlin.ac.uk/species/detail/1398 Accessed on: 17/03/2022

McCauley, R. D., Fewtrell, J., Duncan, A. J., Jenner, C., Jenner, M-N., Penrose, J. D., Prince, R. I. T., Adhitya, A., Murdoch, J. and McCabe, K. (2000) Marine Seismic Surveys – A Study of Environmental Implications. Appea Journal, pp. 692-707.

McConnell, B., Lonergan, M., Dietz, R. (2012) Interactions between seals and offshore wind farms. The Crown Estate, 41 pages. ISBN: 978-1-906410-34-6.

Messieh, S. N., D. J. Wildish, and R. H. Peterson. (1981). Possible impact from dredging and soil disposal on the Miramichi Bay herring fishery. Can. Tech. Rep. Fish. Aquat. Sci., 1008: 33 p

Metcalfe, J.D., B.H. Holford, and G.P. Arnold. (1993). Orientation of plaice (Pleuronectes platessa) in the open sea – evidence for the use of external directional clues. Marine Biology 117:559-566.

Morison F, Harvey E, Franzè G and Menden-Deuer S (2019) Storm-Induced Predator-Prey Decoupling Promotes Springtime Accumulation of North Atlantic Phytoplankton. Front. Mar. Sci. 6:608. doi: 10.3389/fmars.2019.00608

Morley, E.L., G. Jones, A.N. Radford, (2013). The importance of invertebrates when considering the impacts of anthropogenic noise. Proc. R. Soc. B, 281.

Mueller-Blenkle, Christina and Mcgregor, Peter and Gill, A. B. and Andersson, Mathias and Metcalfe, J. and Bendall, Victoria and Sigray, Peter and Wood, Daniel and Thomsen, Frank. (2010). Effects of pile-driving noise on the behaviour of marine fish. Published by Cefas on behalf of COWRIE Ltd.

National Grid (2021a). Scotland to England Green Link (SEGL) ~ Eastern Link 1 Marine Scheme Scoping Report. March 2021.

National Grid (2021b). Scotland to England Green Link (SEGL) ~ Eastern Link 2 Marine Scheme Scoping Report. July 2021.

National Grid Electricity Transmission and Scottish Hydro Electric Transmission plc (2022) Eastern Green Link 2 - Marine Scheme Environmental Appraisal Report Volume 2: Chapter 8 - Benthic Ecology, Accessed on: 11 August 2022, Available at: Eastern Green Link 2 - Chapter 8: Benthic Ecology (marine.gov.scot)

National Grid Electricity Transmission and Scottish Power Transmission (2022) Scotland England Green Link 1 / Eastern Link 1 - Marine Scheme Environmental Appraisal Report Volume 2: Chapter 8 - Benthic Ecology, Accessed on: 11 August 2022, Available at: Microsoft Word - SEGL1_MS_EAR_Chapter 8 Benthic Ecology v4.0_FINAL2.docx (marine.gov.scot)

NatureScot (2020) Priority marine features in Scotlands Seas. Available at: https://www.nature.scot/doc/priority-marine-features-scotlands-seas-habitats Accessed on: 14/03/2022

NatureScot (2021) Feature Activity Sensitivity Tool (FeAST). Available at: https://www.nature.scot/professional-advice/protected-areas-and-species/protected-areas/marine-protected-areas/feature-activity-sensitivity-tool-feast Accessed on: 08/01/2022

Neal, K.J. and Wilson, E. (2008) Cancer pagurus Edible crab. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/species/detail/1179.

Nedelec, S.L., A.N. Radford, S.D. Simpson, B. Nedelec, D. Lecchini, S.C. Mills, (2014). Anthropogenic noise playback impairs embryonic development and increases mortality in a marine invertebrate Sci. Rep., 4 (2014), p. 5891.

Newell, RC. Seiderer, LJ. Hitchcock, DR. (1998) The impact of dredging works in coastal waters: A review of the sensitivity to disturbance and subsequent recovery of biological resources on the seabed. Oceanography and Marine Biology, 36, 127-178.

Newton, M., Main, R. and Adams, C. (2017). Atlantic Salmon Salmo salar smolt movements in the Cromarty and Moray Firths, Scotland. LF000005-REP-1854, March 2017.

Newton, M. Honkanen, H. Lothian, A. and Adams, C (2019) The Moray Firth Tracking Project – Marine Migrations of Atlantic Salmon (Salmo salar) Smolts. Proceedings of the 2019 SAMARCH Project: International Salmonid Coastal and Marine Telemetry Workshop.

Newton, M., Barry, J., Lothian, A., Main, R. A., Honkanen, H., McKelvey, S. A., Thompson, P., Davies, I., Brockie, N., Stephen, A., O'Hara Murray, R., Gardiner, R., Campbell, L., Stainer, P., & Adams, C. (2021). Counterintuitive active directional swimming behaviour by Atlantic salmon during seaward migration in the coastal zone. ICES Journal of Marine Science, 78(5), 1730–1743. https://doi.org/10.1093/icesjms/fsab024

Normandeau (Normandeau Associates, Inc.), Exponent Inc., T. Tricas, T. and Gill, A. (2011) Effects of EMFs from Undersea Power Cables on Elasmobranchs and Other Marine Species. U.S. Dept. of the Interior, Bureau of Ocean Energy Management, Regulation, and Enforcement, Pacific OCS Region, Camarillo, CA.OCS Study BOEMCSARE 2011-09. [online] Available at: http://www.gomr.boemCSAre.gov/PI/PDFImages/ESPIS/4/5115.pdf.

Orpwood, J.E., R.J. Fryer, P. Rycroft, and J.D. Armstrong. (2015) Effects of AC magnetic fields (MFs) on swimming activity in European eels Anguilla anguilla. Scottish Marine and Freshwater Science 6(8):1-22

OSPAR (2008) Assessment of the environmental impact of offshore wind-farms. Available at: https://www.ospar.org/documents?v=7114 Accessed on: 08/01/2022

Parry, G.D. and A. Gason, (2006). The effect of seismic surveys on catch rates of rock lobsters in western Victoria, Australia Fish. Res., 79, pp. 272-284.

Payne, J.F., Andrews, C.A., Fancey, L.L., Cook, A.L., Christian, J.R., (2007). Pilot study on the effects of seismic air gun noise on lobster (Homarus americanus). Canadian Technical Report of Fisheries and Aquatic Sciences No.2712:V + 46.

Pearson W.H., J.R. Skalski, S.D. Skulkin, C.I. Malme, (1992). Effects of Sounds from a Geophysical Survey Device on Behaviour of Captive Rockfish (Sebastes spp.). Canadian Journal of Fisheries and Aquatic Sciences. 49(7): 1343-1356. https://doi.org/10.1139/f92-150

Pearson W.H., J.R. Skalski, S.D. Skulkin, C.I. Malme, (1994). Effects of seismic energy releases on the survival and development of zoeal larvae of Dungeness crab (Cancer magister) Mar. Environ. Res., 38 (1994), pp. 93-113.

Petersen, JK. Malm, T. (2006) Offshore Windmill Farms: Threats to or possibilities for the marine environment. AMBIO, 35, 75-80.

Phua, C. van den Akker, S. Baretta, M. van Dalfsen, J. (2002) Ecological Effects of Sand Extraction in the North Sea. The North Sea Foundation.

Pike, C., Crook, V. & Gollock, M. (2020) Anguilla anguilla. The IUCN Red List of Threatened Species 2020: e.T60344A152845178. https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T60344A152845178.en.

Popper, A. N., Hawkins, A. D., Fay, R. R., Mann, D., Bartol, S., Carlson, Th., Coombs, S., Ellison, W. T., Gentry, R., Hal vorsen, M. B., Lokkeborg, S., Rogers, P., Southall, B. L., Zeddies, D. G. and Tavolga, W. N. (2014) ASA S3/SC1.4 TR-2014 Sound Exposure Guidelines for Fishes and Sea Turtles: A Technical Report prepared by ANSI-Accredited Standards Committee S3/SC1 and registered with ANSI. Springer and ASA Press, Cham, Switzerland.

Popper, A. N., Salmon, M. and Horch, K. W. (2001) Acoustic detection and communication by decapod crustaceans. Journal of Comparative Physiology A, 187 (2): 83-89.

Rikardsen, A.H., Amundsen, P-A., Knudsen, R. Sandring, S. (2006) Seasonal marine feeding and body condition of sea trout (Salmo trutta) at its northern distribution. ICES Journal of Marine Science, Volume 63, Issue 3, 2006, Pages 466–475.

Roach, M., Cohen, M., Forster, R., Revill, A. S., and Johnson, M. (2018) The effects of temporary exclusion of activity due to wind farm construction on a lobster (Homarus gammarus) fishery suggests a potential management approach. – ICES Journal of Marine Science, 75: 1416–1426.