9. Fish and Shellfish Ecology

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

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

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

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

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

9.6.1.    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

9.7.1.    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

9.8.1.    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

9.9.1.    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