11. Offshore and intertidal ornithology

11.1. Introduction

1. This chapter of the Offshore Environmental Impact Assessment Report (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 “the Proposed Development”) on offshore and intertidal ornithology. Specifically, this chapter considers the potential impact of the Proposed Development seaward of Mean High Water Springs (MHWS) during the construction, operation and maintenance, and decommissioning phases.
2. “Likely Significant Effect (LSE)” is a term used in both the “EIA Regulations” and the Habitat Regulations. Reference to LSE in this offshore EIA report refers to “LSE” as used by the “EIA Regulations”. This offshore EIA report is accompanied by a Report to Inform Appropriate Assessment (RIAA) which uses the term LSE as defined by the Habitat Regulations Assessment (HRA) Regulations.
3. The assessment presented is informed by the following technical chapters:

• volume 2, chapter 7: Physical Processes;
• volume 2, chapter 9: Fish and Shellfish Ecology;
• volume 3, appendix 11.1: Baseline Ornithology Technical Report;
• volume 3, appendix 11.2: Ornithology Inter-tidal Survey Report;
• volume 3, appendix 11.3: Ornithology Collision Risk Modelling Technical Report;
• volume 3, appendix 11.4: Ornithology Displacement Technical Report;
• volume 3, appendix 11.5: Ornithology Apportioning Technical Report;
• volume 3, appendix 11.6: Ornithology Population Viability Assessment Technical Report;
• volume 3, appendix 11.7: Boat-based Survey Report; and
• volume 3, appendix 11.8: Offshore Ornithology Road Map.

11.2. Purpose of this Chapter

4. 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.
5. In particular, this offshore and intertidal ornithology 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 effects on offshore and intertidal ornithology arising from the Proposed Development and reaches a conclusion on the likely significant effects on offshore and intertidal ornithology, based on the information gathered and the analysis and assessments 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 offshore and intertidal ornithology.

11.3. Study area

6. Three study areas have been used to inform this chapter of the Offshore EIA Report. These are listed below, with further detail provided in the following sections:

• Offshore Ornithology regional study area;
• Offshore Ornithology study area; and
• Intertidal Ornithology study area.

11.3.1.              Offshore Ornithology Regional study area

7. The Offshore Ornithology regional study area was determined by the area within which potential impacts to breeding seabirds could occur and was based on the foraging ranges of breeding seabirds. Many seabirds have large foraging ranges which in some cases extend several hundred kilometres from their breeding colonies. Birds may therefore overlap (i.e. have connectivity with) the Proposed Development, even when the colonies they originate from are a significant distance away. The Offshore Ornithology regional study area therefore also encompasses the Special Protection Area (SPA) breeding colonies with potential connectivity to the Proposed Development during the breeding season ( Figure 11.1   Open ▸ ).
8. Published mean-maximum foraging ranges (plus one standard deviation (+1 S.D.)) in Woodward et al. (2019) were used to define the Offshore Ornithology regional study area. Gannet has the largest foraging range (315.2 km ± 194.2 km) of the key species considered in the ornithology assessment. The Offshore Ornithology regional study area therefore extends 509.4 km from the Proposed Development ( Figure 11.1   Open ▸ ). Search areas for SPA breeding colonies and regional search areas for other key species in the assessment will fall within the mean-maximum foraging range of gannet. Therefore, this approach is appropriate to define the maximum extent of the Offshore Ornithological regional study area.
9. A seabird colony that is affected by the potential impacts of the Proposed Development could also be affected by the potential impacts at other developments within the foraging range of breeding seabirds from that colony. The cumulative study area for each species will therefore be defined by implementing a search area equivalent to the species-specific mean-maximum foraging range (+ 1 S.D.) along a marine pathway, from those potentially affected breeding colonies of that species.
10. In the non-breeding season, seabirds are not constrained by colony location and, depending on individual species, range widely within United Kingdom (UK) seas and beyond. The Zone of Influence (ZoI) for seabird species in the non-breeding season (where an assessment is deemed to be required) is based on Furness (2015) which presents Biologically Defined Minimum Population Scales (BDMPS).

Figure 11.1: Offshore Ornithology Regional Study Area

 Figure 11.2: Offshore Ornithology Study Area

11.3.2.              Offshore Ornithology study area

11. The area covered by the baseline digital aerial surveys encompasses the Proposed Development array area, plus a 16 km buffer, which makes up the Offshore Ornithology study area (Figure 11.2). For the purposes of the assessment on bird impacts data obtained within the 16 km buffer area have been used to provide context in relation to the Proposed Development array area.
12. Using this extensive study area provides a wide ornithological context for the Proposed Development. It is also an appropriate size to provide a robust pre- and post-construction comparison of seabird abundance and distribution along a gradient outward from the Proposed Development and to allow this to be monitored.
13. The Proposed Development export cable corridor beyond the 16 km buffer area was not included in the digital aerial survey area. Based on the predicted level of impact arising from cable laying on seabirds the use of existing data sources is considered sufficient to characterise baseline characteristics of the Proposed Development export cable corridor for the purposes of the EIA Report. This approach was discussed at Ornithology Road Map Meeting 2 and further discussed and agreed at Ornithology Road Map 6 (see volume 3, appendix 11.8).
14. It should be noted that the digital aerial dataset collected within the Proposed Development offshore ornithology study area was re-analysed with reference to the Proposed Development boundary refinement process that was undertaken in June 2022, so that all figures presented in this chapter and the supporting documents regarding the Proposed Development reflect this boundary refinement.

11.3.3.              Intertidal Ornithology study area

15. The offshore topic of offshore and intertidal ornithology includes an area of intertidal habitat seaward of MHWS and landward of Mean Low Water Springs (MLWS). This intertidal area overlaps with the onshore topic of ecology and ornithology (landward of MHWS).
16. The Intertidal Ornithology study area for the assessment of effects on birds in the intertidal zone covers the coastal area between MHWS and MLWS at the landfall locations within which intertidal bird surveys have been carried out in the non-breeding season. The Intertidal Ornithology study area extends approximately 6 km along the coast to cover the two landfall locations that were covered during the surveys and extends up to 1.5 km seaward from MHWS (Figure 11.3). However, it should be noted that only the northern landfall location at Skateraw is now being considered. Survey data from the southern landfall location was included in the assessment process to provide greater context.

Figure 11.3: Intertidal Ornithology Study Area

11.4. Policy and Legislative Context

17. Policy and legislation on renewable energy infrastructure is presented in volume 1, chapter 2 of the Offshore EIA Report. Policy specifically in relation to offshore and intertidal ornithology, is contained in the Scottish National Marine Plan (NMP) (Scottish Government, 2015). A summary of the legislative provisions relevant to offshore and intertidal ornithology are provided in Table 11.1   Open ▸ , with other relevant policy provisions set out in Table 11.2   Open ▸ . Further detail is presented in volume 1, chapter 2.

Table 11.1: Summary of Legislation Relevant to Offshore and Intertidal Ornithology

Table 11.2: Summary of NMP Policies Relevant to Offshore and Intertidal Ornithology

11.5. Consultation

18. The offshore and intertidal ornithology Road Map is 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 agreeing to 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 submission documents is on likely significant environmental effects as required by the EIA Regulations.
19. A summary of the key issues raised during consultation activities undertaken to date specific to offshore and intertidal ornithology is presented in Table 11.3   Open ▸ below, together with how these issues have been considered in the production of this offshore and intertidal ornithology EIA Report chapter and associated appendices. Further detail is presented within volume1, chapter 5. Additional information on the Road Map process relevant to offshore and intertidal ornithology is presented in Appendix 11.8.

Table 11.3: Summary of Key Consultation Issues Raised During Consultation Activities Undertaken for the Proposed Development Relevant to Offshore and Intertidal Ornithology

11.6. Methodology to Inform Baseline

11.6.1.              Desktop Study

20. Information on offshore and intertidal ornithology within the Offshore Ornithology regional study area was collected through a detailed desktop review of existing studies and datasets. These are summarised in Table 11.4   Open ▸ below.

Table 11.4: Summary of Key Desktop Reports and Datasets

21. Additional datasets used for the desktop review are presented in Table 2.1.1 of volume 3, appendix 11.1.

11.6.2.              Identification of Designated Sites

22. All designated sites within the Offshore Ornithology regional 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 below:

• Step 1: All designated sites of international, national and local importance within the Offshore Ornithology regional study area were identified using a number of sources. These sources included published information on Special Protection Areas (SPAs) for birds such as the NatureScot website.
• Step 2: Information was compiled on the relevant qualifying interest features for each of these sites. Key information included most recently available population count or estimate from the Seabird Monitoring Programme (SMP) online database, as well as published information on the mean maximum foraging range (plus 1 S.D.). This information was taken from the most recent available source (Woodward et al. 2019).
• 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, including the Proposed Development export cable corridor;

–           The Proposed Development is located within mean maximum foraging range (+1SD) of any species of qualifying interest from designated sites; or

–           Designated sites are within the potential ZoI for impacts associated with the Proposed Development.

23. This information was used within the EIA Report assessment to determine the conservation importance of features present in the Offshore Ornithology regional study area.

11.6.3.              Site-Specific Surveys

24. To inform the offshore and intertidal ornithology EIA Report chapter, site-specific surveys were undertaken, as agreed with Marine Scotland Licencing Operations Team (MS-LOT), Marine Scotland Science (MSS), NatureScot and Royal Society for the Protection of Birds (RSPB). A summary of the surveys undertaken to inform the offshore and intertidal ornithology impact assessment are outlined in Table 11.5   Open ▸ below.

Table 11.5: Summary of Site-Specific Survey Data

25. The following secondary data sources have also been used to provide relevant supplementary contextual information on the Proposed Development array area and surrounding buffer area:

• Boat-based transect survey data from July and August 2020 and between April and May 2021 within the Proposed Development targeted at recording seabird flight height and behaviour and collecting associated environmental variable data (volume 3, appendix 11.7);
• Boat-based transect survey data of the Firth of Forth Round 3 Zone from December 2009 to November 2011; and
• Seabird colony data and seabird tracking data from Forth Islands, Fowlsheugh and St Abb’s Head collected between 2010 and 2019.
  26. Methods used and results from the site-specific digital aerial surveys are presented in section 4 of volume 3, appendix 11.1.

11.7. Baseline Environment

11.7.1.              Overview of Baseline Environment

27. A summary of the baseline environment for offshore and intertidal ornithology is provided in the following sections. Full details of the analysis undertaken to develop the offshore and intertidal ornithology baseline is provided in volume 3, appendix 11.1, which includes information on survey design and methods, as well as the analysis techniques implemented to characterise the baseline.

Offshore Ornithology

28. Seabird abundance estimates from the site-specific digital aerial surveys and how they were derived are presented in detail in volume 3, appendix 11.1. Detail from the baseline report has not been repeated within this chapter in order to present a clear and concise impact assessment.
29. Species assessed for impacts are those which were recorded during digital aerial surveys and which are considered to be at potential risk either due to their abundance, potential sensitivity to wind farm impacts or due to biological characteristics (e.g., commonly fly at rotor heights) which make them potentially susceptible. The conservation status of these species is provided in Table 11.6   Open ▸ . Abundances and distributions of all species observed are presented in volume 3, appendix 11.1.

Table 11.6: Summary of Nature Conservation Status of Seabird Species Considered at Risk of Potential Impacts

1 Stanbury et al., 2021

30. Impacts have been assessed in relation to relevant biological seasons, as defined by NatureScot (2020), and a summary of these seasons for seabird species is presented in Table 11.7   Open ▸ . Seasons for three species (sooty shearwater, pomarine skua and little auk) are not defined by NatureScot, so these species are not listed.

Table 11.7: Seasonal Definitions for Seabird Species (based on NatureScot, 2020)

31. For the breeding season, the regional reference population for seabird species in the breeding season was calculated by summing the most recent colony counts from the SMP online database within mean-maximum foraging range (+1 S.D.) where available, as defined in Woodward et al. (2019). For the non-breeding period, the relevant BDMPS and associated population estimates were taken from Furness (2015) ( Table 11.8   Open ▸ and Table 11.9   Open ▸ ).

Table 11.8: Mean-maximum foraging distance + 1S.D. used for Seabird Species

Table 11.9: Breeding and non-breeding reference populations for seabird species

1 – Regional breeding populations within mean maximum foraging range only (volume 3, appendix 11.1). Manx shearwater is not included as there are no east coast breeding colonies (NatureScot, 2016)
2 – As advised in Scoping Opinion

Intertidal Ornithology

32. The Intertidal Ornithology study area comprised two separate landfall locations and their associated sections of export cable corridor (Figure 11.3). The length of shoreline surveyed covered approximately 6 km to ensure contemporary data were collected for all potential export cable landfall locations under investigation. Since the completion of the intertidal survey work, further analysis has been undertaken and the most southerly landfall site has been removed from the Proposed Development. The northern landfall location at Skateraw is therefore the remaining landfall option. 
33. The programme of monthly intertidal and nearshore coastal bird surveys was conducted over 12 months between July 2020 and June 2021 inclusive. The survey programme included all key periods relating to bird interests and designated sites, specifically breeding and non-breeding seasons, plus spring and autumn passage. For comparison, WeBS count data were obtained from the BTO for the most recent high tide datasets gathered from the survey area which most closely corresponded to the intertidal ornithology study area.
34. The intertidal and nearshore bird survey data demonstrate that the Intertidal Ornithology study area supports a diversity of bird species typical of coastal areas off the east coast of Scotland, predominantly seaducks, wading birds, divers, grebes and other seabirds, primarily in the non-breeding season.
35. A total of 55 species were recorded within the intertidal and nearshore survey area during the survey programme. A total of 14 species of wildfowl were recorded, along with 15 species of waders, two diver species, two grebe species, ten species of gulls and terns and 12 species of seabirds.
36. The available WeBS data corresponded relatively closely with the intertidal and nearshore bird survey data. This demonstrated that the survey data were a robust representation of the diversity and abundance of the birds which typically occurs within the Intertidal Ornithology study area.
37. The intertidal shore and nearshore waters of the Iintertidal ornithology study area are typically of local importance for the majority of qualifying species for SPAs, Ramsar sites and Site of Special Scientific Interest (SSSIs) associated with the Firth of Forth.
38. Further information of the methods used and results from the intertidal bird surveys are presented in volume 3, appendix 11.2.

11.7.2.              Designated Sites

39. Key designated sites identified for the offshore and intertidal ornithology chapter are described in Table 11.10   Open ▸ . Typically, these are the closest designated sites to the Proposed Development that support important populations of breeding seabirds. Additional, more distant conservation sites considered for ornithological connectivity with the Proposed Development are detailed in volume 3, appendix 11.5.

Table 11.10: Key Designated Sites and Relevant Qualifying Interest Features for the Offshore and Intertidal Ornithology Chapter

11.7.3.              Important Ecological Features

40. Important Ecological Features (IEFs) can be 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. In an ornithological context, IEFs can be attributed to individual key species (such as herring gull) or species groups (for example other gulls). Each IEF is assigned a value or importance rating which is based on ecological and conservation importance, for example a key species listed as a feature of an SPA. Table 11.11   Open ▸ details the criteria used for determining the importance of these key species and Table 11.12 presents the defining characteristics for classification of these key species, providing justifications for importance rankings for the key species likely to occur within the Offshore Ornithology study area, as well as a means to scope out species from further assessment on the basis of their importance. Specific reference is made to each species’ conservation and ecological importance, where this is known. For the purposes of this assessment, the key species are those that are screened in for assessment in Table 11.12. These key species will be taken forward for assessment.

Table 11.11: Defining Criteria

Table 11.12: Initial Scoping of Key Species within the Offshore Ornithology study area

11.7.4.              Future Baseline Scenario

41. The EIA Regulations ((The Electricity Works (Environmental Impact Assessment) (Scotland) Regulations 2017, The Marine Works (Environmental Impact Assessment) (Scotland) Regulations 2017 and The Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2017)), require that “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.
42. 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.
43. 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. In this context, the future baseline scenario at this particular location would involve environmental changes such as climate change and established activities such as commercial fishing activity in the area, as well as the construction and operation of up to three other offshore wind farms to the north and west.
44. 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). As highlighted in volume 2, chapter 9 and volume 3, appendix 20, changes in sea 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. These changes will lead to changes in prey distribution and availability, which in turn will affect the seabird species that prey on these fish species, ultimately resulting in ecosystem and population level effects.
45. 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.

11.7.5.              Data Limitations and Assumptions

46. The data sources used in this chapter are detailed in Table 11.4   Open ▸ and Table 11.5   Open ▸ , with additional relevant information from volume 3, appendix 11.1. The desktop data used are the most up to date publicly available information which can be obtained from the applicable data sources as cited.
47. There is a high degree of variability in the marine environment, both spatially and temporally. However, as the baseline site characterisation for this Offshore EIA Report has been based on two years of digital aerial survey data, it is considered to be representative of the Proposed Development array area and surrounding buffer area for the purpose of impact assessment.
48. It was not always possible to complete digital aerial surveys every month, due to poor weather conditions in April 2019 and January 2020, and due to Covid-19 restrictions in April 2020. To make up for the missed January 2020 survey, two surveys were undertaken in February 2020, with results from the first of these (5/2/20) being used as a proxy for the January 2020 survey. As a result of Covid-19 disruption in April 2020, an additional survey was flown on 5th May 2020. In addition, two surveys were flown in April 2021, with the first of these being used as a proxy for the missed March 2021 survey, and the second April 2021 survey being used as a proxy for the missed survey in April 2019. Further details of survey coverage are presented in volume 3, appendix 11.1.
49. Surveys of the intertidal and near-shore area in the vicinity of the export cable landfall options were carried out to provide data in relation to potential impacts on estuarine birds in the vicinity. A programme of ‘through the tide’ surveys was designed to capture the numbers and distribution of birds in the intertidal and near-shore area throughout the year and over the full tidal cycle. Surveys were carried out in suitable weather conditions (avoiding times of low visibility and heavy precipitation) and there were no data gaps due to prolonged adverse weather. The intertidal surveys are considered to fulfil the industry standard requirements with no limitations or data gaps in this respect.
50. Given the limited scale of works required for the export cable corridor (i.e. a relatively small number of vessel movements over a relatively small area for a short period of time), no specific surveys were commissioned for the area between the Offshore Ornithology study area and the Intertidal Ornithology study area (i.e. within 1.5 km from MHWS, covered by shore-based surveys). Instead, the assessment for this section of the export cable corridor makes use of published data on the presence of birds from the desk study (volume 2, appendix 11.2). This approach was agreed at Road Map Meeting 6 on 10 May 2022, (see volume 3, appendix 11.8).
51. As there is a potential lack of data pertaining to pulses of passage movements by migratory waterbirds over or through the Proposed Development, Scoping Opinion advice was to assess these species with reference to site-specific survey results and the Marine Scotland commissioned update to the 2014 report on ‘strategic assessment of collision risk of Scottish offshore wind farms to migrating birds’ (WWT, 2014).
52. As of August 2022, this updated report was not publicly available therefore this assessment relies upon the Scoping Opinion advice which was to assess any SPA migratory waterbird species relevant to the Proposed Development which are not considered in the 2014 Report on a qualitative basis. Therefore, the collision assessment for migratory species was conducted based on the WWT (2014) report, with any SPA migratory waterbird species relevant to the Proposed Development which are not considered in the 2014 Report being assessed on a qualitative basis.

11.8. Key Parameters for Assessment

11.8.1.              Maximum Design Scenario

53. The maximum design scenarios identified in Table 11.13   Open ▸ have been selected as those having the potential to result in the greatest effect on an identified receptor or receptor group. 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 11.13: Maximum Design Scenario Considered for the Assessment of Potential Impacts on Offshore and Intertidal Ornithology

11.8.2.              Impacts Scoped out of the Assessment

54. The offshore and intertidal ornithology Road Map process (volume 3, appendix 11.8) has been used to facilitate stakeholder engagement on topics to be scoped out of the assessment.
55. On the basis of the baseline environment and the project description outlined in volume 1, chapter 3 of the Offshore EIA Report, one impact is proposed to be scoped out of the assessment for offshore and intertidal ornithology. This was agreed with key stakeholders through consultation ( Table 11.14   Open ▸ ).

Table 11.14: Impacts Scoped Out of the Assessment for Offshore and Intertidal Ornithology Chapter

11.9. Impact Assessment Methodology

11.9.1.              Overview

56. The offshore and intertidal ornithology impact assessment has followed the methodology set out in volume 1, chapter 6 of the Offshore EIA Report, with some adaptations to make it applicable to ornithology receptors. Specific to the offshore and intertidal ornithology chapter, the following guidance documents have also been considered:

• Band, W., M. 2012. Using a collision risk model to assess bird collision risks for offshore windfarms. Final version, August 2012. SOSS, The Crown Estate;
• Butler et al., 2020. Attributing seabirds at sea to appropriate breeding colonies and populations (CR/2015/18). Scottish Marine and Freshwater Science Vol 11 No 8, 140pp. DOI: 10.7489/2006-1;
• CIEEM, 2022. Guidelines for Ecological Impact Assessment in the UK and Ireland: Terrestrial, Freshwater, Coastal and Marine version 1.2.
• King et al., 2009. Guidance on ornithological cumulative impact assessment for offshore wind developers;
• Maclean et al., 2009. Assessment methodologies for offshore wind farms;
• Natural England nepva tools (Searle et al., 2019, Mobbs et al., 2020)
• NatureScot. 2020. Seasonal Periods for Birds in the Scottish Marine Environment;
• NatureScot. 2018. Interim Guidance on Apportioning Impacts from Marine Renewable Developments to Breeding Seabird Populations in Special Protection Areas; and
• Statutory Nature Conservation Bodies (SNCB). (2017). Interim Displacement Advice Note. Advice on how to present assessment information on the extent and potential consequences of seabird displacement from Offshore Wind Farm developments.

57. In addition, the offshore and intertidal ornithology impact assessment has considered the legislative framework as defined in Table 11.1   Open ▸ .

11.9.2.              Impact Assessment Criteria

58. 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.
59. The criteria for defining magnitude levels for ornithology receptors in this chapter are outlined in Table 11.15   Open ▸ below. This set of criteria has been determined on the basis of changes to bird populations. As a guide, it has been based on summing predicted adult mortality in the breeding season and mortality of all age classes in the non-breeding season and presenting this figure as an overall percentage increase in the baseline mortality in terms of the regional population. A guide percentage has been included for each of the categories of impact magnitude in Table 11.15   Open ▸ . Where possible, the predicted magnitude has also been sense-checked against relevant PVA outputs for the species under consideration, which may revise the magnitude rating, depending on the PVA predictions.

Table 11.15: Definition of Terms Relating to the Magnitude of an Impact

60. For ornithology, the sensitivity of a species is one of the core components of the assessment of potential impacts and their effects on birds. There is also a need to consider the conservation importance of each species when making a decision on the definition of the overall sensitivity of any particular species to any potential impact or effect. As part of making that decision, account has to be taken on a species by species basis, bearing in mind that a species with a high conservation importance may not be sensitive to a specific effect, while a species with a low conservation importance might be very sensitive to the effect. For example, herring gull is a species listed as a qualifying feature for some SPAs and has a conservation concern listing of ‘Red’ because of recent population declines (Stanbury et al, 2021), but cannot be judged to be sensitive to disturbance as many individuals regularly exploit human sources of food and nest on buildings in busy cities. Red-throated diver however, is also a species listed as a qualifying feature for some SPAs, but is ‘Green-listed’ in the most recent Birds of Conservation Concern rankings (Stanbury et al, 2021), but is considerably more sensitive to human-related disturbance than herring gull.
61. Taking account of such differences between species is an important part of the overall process of determining the potential significance of an impact and this should be applied where needed as a method to modify the sensitivity of an effect assigned to a specific receptor.
62. Previous reviews have ranked individual seabird species for their sensitivity to potential impacts such as collision, disturbance and displacement (e.g. Furness and Wade, 2012, Furness et al., 2013, Bradbury et al., 2014, Dierschke et al., 2016). Conclusions from these reviews have been used to inform definitions of sensitivity for bird species ( Table 11.16   Open ▸ ).

Table 11.16: Definition of Terms Relating to the Sensitivity of the Receptor

63. The conservation importance of receptor species is based on the status of the population from which individuals are predicted to originate from. For this assessment, conservation importance is primarily related to the degree of connectivity of receptor species to SPAs in the region. Example criteria for defining conservation importance in this chapter are outlined in Table 11.11   Open ▸ . Additional consideration has also been given to the current BoCC5 national conservation status for particular species, where appropriate (Stanbury et al, 2021).
64. The significance of the effect upon offshore and intertidal ornithology is determined by correlating the magnitude of the impact and the sensitivity of the receptor ( Table 11.17   Open ▸ ). In addition, the conservation importance of the receptor is also considered using expert judgement to sense-check the matrix outcome.
65. In cases where a range is suggested for the significance of effect, there remains the possibility that this may span the significance threshold (i.e. the range is given as minor to moderate). In such cases the final significance is based upon the expert's professional judgement as to which outcome delineates the most likely effect, with an explanation as to why this is the case.
66. For the purposes of this assessment:

• a level of effect of moderate or more will be considered a ‘significant’ effect in terms of the EIA Regulations; and
• a level of effect of minor or less will be considered ‘not significant’ in terms of the EIA Regulations.
  67. 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. However, it should be noted that while minor impacts are not significant in their own right, it is important to distinguish these from other non-significant impacts as they may contribute to significant impacts cumulatively or through interactions.

Table 11.17: Matrix Used for the Assessment of the Significance of the Effect

11.9.3.              Designated Sites

68. Where Natura 2000 sites (i.e., nature conservation sites in Europe designated under the Habitats or Birds Directives[3]) 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 the key sites as described within section 11.7.2 of this chapter, and more distant conservation sites detailed in volume 3, appendix 11.5.The assessment of the potential impacts on the site itself are deferred to the RIAA for the Proposed Development. A summary of the outcomes reported in the RIAA is provided in section 11.15 of this chapter.
69. 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 European site has 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 European site (i.e., a separate assessment for the local or national site is not undertaken). However, where a local or nationally designated site falls outside the boundaries of a European site, but within the Offshore Ornithology regional study area, an assessment of the LSEs on the overall site is made in this chapter using the EIA methodology.