Sectoral marine plan for offshore wind energy: strategic habitat regulations appraisal pre-screening report

4 Method and Scope of the Appraisal

4.1 Introduction

4.1.1 This section presents a clear description of the proposed approach for undertaking the screening and assessment stages of the HRA process for the draft Plan in fulfilment of Stage 4 of the HRA (see Figure 4). This methodology draws upon the principles set out in past plan-level HRAs (as listed in Section 2.3), whilst recognising the lessons learned and our latest understanding of the impacts associated with offshore wind development and the sensitivities and specific behaviours of interest features.

4.2 Screening Methodology

4.2.1 The screening process will involve reviewing and then screening either in or out the relevant European/Ramsar sites and associated qualifying interest features for which there could be LSE (or the potential for LSE cannot be excluded) as a result of the Plan. This will include reviewing sites that lie within the initial pre-screening buffer zone, as well as sites beyond this buffer that support highly mobile species which use or traverse across the Plan area (or AoS or DPO areas). If more detail emerges about the Plan as the SA process progresses (e.g. possible cable alignments and cable landfall positions), then the HRA screening and subsequent assessment could be more focussed as appropriate.

4.2.2 The screening methods that are proposed for each of the following key interest feature groups of habitats and species ^[7] are outlined below:

• Habitats and associated species;
• Birds;
• Marine mammals (cetaceans and seals);
• Migratory fish and freshwater pearl mussel;
• Otters; and
• Bats.

4.3 Habitats and Associated Species

4.3.1 The screening methods for this interest feature group need to consider the potential for both direct and indirect LSEs on habitats and associated non-mobile ^[8] species (see Tables A1 and A2 in Appendix A). The first step will therefore be to screen out (i.e. remove from the pre-screening list, Table A3 in Appendix A) any terrestrial/ freshwater habitats and associated species interest features for which there will be no LSE on the basis that there is definitely no impact pathway (i.e. no potential physical or ecological connectivity with any marine activities resulting from the Plan).

4.3.2 Terrestrial features screened out by this first step will include woodland, peatlands, heaths and bogs, as well as species associated with such terrestrial habitats e.g. snail species. It is recognised that there is a potential for terrestrial sites located on the coast to be affected where they occur in the vicinity of proposed cable landfall locations (noting that the locations of such landfalls are not known at this stage). Where terrestrial sites have a coastal habitat feature (e.g. dunes, coastal lagoons, inlets, caves and sea cliffs) and associated species then these sites and features will remain ‘screened in’ and taken forward into the next stage of the HRA.

4.3.3 Freshwater habitats and species screened out by this step will include water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation; oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoëto-Nanojuncetea, alluvial forests with Alnus glutinosa and Fraxinus excelsior and floating water-plantain.

4.3.4 Non-migratory freshwater species will also be screened out, including great crested newts, white-clawed (or Atlantic stream) crayfish, and brook lamprey. However, freshwater pearl mussel will be screened in because it has a life cycle connection with Atlantic salmon (see Section 4.6).

4.3.5 The next step will be to screen in (i.e. retain from the pre-screening list, Table A3 in Appendix A), all marine habitat features and associated species that lie within the Plan area (or any defined AoS or DPO areas) because, clearly, they may be directly or indirectly affected by activities undertaken within the plan boundaries.

4.3.6 Activities within the Plan area (or any defined AoS or DPO areas) may have an indirect effect on habitat features and associated species just outside the boundaries (e.g. from hydrodynamic and/or sediment transport changes). To identify the European/Ramsar sites outside these areas for which there could be such potential indirect effect, the results from a previously run UK-wide hydrodynamic model ^[9] (as illustrated in Figure 9) will be used to identify the area of sea located within one tidal excursion of the boundaries of the Plan area (or any defined AoS or DPO areas). These tidal excursions will be interpolated where there are any gaps in the data (i.e. outside of the UK, in Republic of Ireland waters).

Figure 9: Tidal ellipse distances in the UK

4.3.7 This approach will be adopted because the nature of the tide is such that its movement is typically described as an almost closed ellipse. These ellipses can be viewed as a package of water that will move to and fro over one tidal cycle, typically along a dominant axis, returning to almost the same position. As such, they can also be used to identify the maximum likely distance that water, or any material in suspension or solution it may contain, might be tidally transported from a given location or area. Evidence from plume studies indicates that even fine particles mobilised from the seabed settle out again to a large extent within the distance of one tidal excursion

4.3.8 or the screening process, the ellipses will be mapped and those ellipses that lie closest to the boundary of the Plan area (or any defined AoS or DPO areas) will be selected and will then be ‘moved' on the map to touch the nearest boundary point of that area or areas. This will result in the Plan area (or each discrete AoS or DPO areas) having a series of ellipses around its boundary. To then determine how far, and in which direction, a parcel of water will move from this boundary edge and then return, a line will be drawn between the furthest limit of each of these tidal ellipses. This new line will define a zone for screening habitat features and associated species that could be potentially indirectly affected by the Plan. The average distance over which there could be a potential indirect effect, as defined by a mean spring tidal ellipse, is typically around 10-15 km (Figure 9).

4.3.9 To summarise the approach described above, the following iterative series of steps encompass the proposed screening methods for the habitat and associated species interest feature group:

• Step 1: Identify the best understanding about possible cable alignments and landfall positions to make assumptions and, if possible, identify ‘areas of search’ for these locations;
• Step 2: Screen out (i.e. remove from the pre-screening list, Table A3 in Appendix A) all European/Ramsar sites supporting terrestrial/freshwater habitats and non-mobile species interest features for which there will be no LSE on the basis that there is definitely no impact pathway;
• Step 3: Screen in (i.e. retain in the pre-screening list, Table A3 in Appendix A) all European/Ramsar sites supporting marine/coastal habitats and non-mobile species interest features that overlap with the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls and will therefore be directly affected;
• Step 4: Undertake a review of tidal excursion patterns (including interpolation where necessary) and draw a new boundary at a distance of one tidal excursion from the boundaries of the Plan Area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 5: Screen in all European/Ramsar sites supporting marine/coastal habitats and non-mobile species interest features that could be indirectly affected because they lie at distances of less than one tidal ellipse from the Plan Area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 6: Screen out all European/Ramsar sites supporting marine/coastal habitats and non-mobile species interest features that lie beyond one tidal ellipse from the Plan Area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls and will definitely not be affected indirectly by changes to the hydrodynamic and sediment regime;
• Step 7: Produce a screening table (i.e. update the pre-screening list in Table A3 in Appendix A based on the previous steps) to indicate the European/Ramsar sites and supporting terrestrial, freshwater, coastal and marine habitat and non-mobile species interest features that have been screened in or out of the assessment. Produce accompanying maps of screened in European/Ramsar sites within and adjacent to the Plan Area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 8: Identify any plan-level mitigation measures that can be applied to ensure that there is no LSE on the screened in European/Ramsar sites and their qualifying interest features and, where possible, screen such features or sites out on this basis; and
• Step 9: Update the screening table and maps with the final list of screened in European/Ramsar sites and qualifying interest features.

4.4 Birds

4.4.1 The screening methods for this interest feature group need to consider the potential LSE from both direct and indirect sources of change (see Tables A1 and A2 in Appendix A). The first step will therefore be to screen out (i.e. remove from the pre-screening list, Table A3 in Appendix A) a number of bird qualifying interests on the basis that there would be no impact pathway associated with the draft Plan. These are birds which are entirely resident within inland terrestrial habitats, do not forage at sea or migrate over marine water bodies and do not migrate internationally. The bird interest features are Red Billed Chough, Western Capercaillie, Scottish Crossbill, Fair Isle Wren and Eurasian Marsh Harrier.

4.4.2 A number of bird species that are qualifying interests of SPAs as breeding populations only will also be screened out because they will be largely confined to these areas during the breeding period. These bird species are Hen Harrier, Merlin, Eurasian Dotterel, Spotted Crake, Peregrine, Grey Heron, Little Stint, Curlew, Sandpiper, Osprey and Short-eared Owl. These species will however be screened in (i.e. retained in the pre-screening list, Table A3 in Appendix A) where they are roosting and/or wintering qualifying interests of the relevant European/Ramsar sites because there could be a movement of birds outside the SPAs.

4.4.3 For breeding and resident populations of Golden Eagle, these will be screened in where they are qualifying features of coastal European/Ramsar sites (due to potential effects on foraging, prey and/or from disturbance). They will be screened out where they are features of inland European/Ramsar sites in which case there will be no LSE.

4.4.4 The next step will be to consider the foraging behaviour of coastal and offshore bird colonies (whether these are overwintering or breeding populations). Based on previous baseline literature reviews that have been undertaken of bird for past plan-level HRAs (e.g. ABPmer, 2014; 2017), it is known that most birds typically forage within 100 km of breeding sites and will therefore be included at pre-screening. There are a number of species that forage over greater distances and could be affected even though they lie outside the pre-screening buffer zone. This list of species is expected to include the following:

• Atlantic Puffin (105 km);
• Lesser Black-backed Gull (141 km);
• Manx Shearwater (330 km);
• Northern Fulmar (400 km); and
• Northern Gannet (229 km).

4.4.5 In each case the ‘mean maximum’ foraging distances are provided in brackets. This distance is defined as the maximum range reported by individual studies averaged across studies (Thaxter et al., 2012). A number of past plan-level HRAs used the ‘maximum’ foraging distances recorded across all studies as opposed to the ‘mean maximum’ to determine the distance that European/Ramsar sites with offshore seabird interest features should be screened into the assessment (e.g. ABPmer, 2011; 2013, MMO, 2013). More recent HRAs have altered their screening approach to offshore seabirds. The HRA for The Crown Estate’s Offshore Floating Wind Plan in Scotland ( AMEC, 2014) used the mean maximum foraging range of Northern Fulmar (400 km) as a worst case screening buffer for all breeding bird populations. For the UK-wide HRA for The Crown Estate’s Wave and Tidal Further Leasing Plan (ABPmer, 2014), the Statutory Nature Conservation Bodies ( SNCBs) from each of the four UK devolved administrations agreed that the ‘mean maximum’ distances provided a more relevant but still sufficiently precautionary approach to screening offshore seabirds. This approach is proposed to be used for the draft Plan HRA.

4.4.6 Although foraging distances are fairly well understood, less information is available to indicate foraging directions and it is known that they can be very variable. Based on evidence from available FAME data, seabirds are unlikely to travel over large tracts of land when foraging (Mark Bolton, RSPB, pers. comm.). It is therefore assumed that seabirds will not travel across significant land masses (greater than 50 km) when foraging over long distances. Any SPAs for long-distance foraging bird interest features occurring outside of the 100 km buffer and beyond a minimum landmass distance of 50 km will therefore be screened out of the assessment. Very few additional European/Ramsar sites are actually likely to be screened out of the assessment following the application of these criteria but it is considered important that these principles are clearly followed and adopted in the light of the latest information about bird foraging and European/Ramsar site locations. This follows the approach that was applied in the recent national plan-level HRA for The Crown Estate’s Wave and Tidal Further Leasing plan (ABPmer, 2014).

4.4.7 There are qualifying bird species within non- UK sites which are not a qualifying interest feature for UK sites but could forage and/or migrate internationally. These include the following Annex I species:

• Balearic Shearwater - Despite breeding in the Balearic Islands and the south coast of France, it migrates north towards the Bay of Biscay, which is when some birds make it into British waters ( RSPB, 2018);
• Common Crane - Small numbers of this species pass mainly through southern and eastern parts of Britain in spring and autumn, and there is a tiny breeding population in eastern England ( RSPB, 2018). It is mainly found on inland freshwater wetland habitats. This species is on the ‘Amber’ list and is considered to be of ‘Least Concern’ (BirdLife International, 2018; RSPB, 2018);
• Cory’s Shearwater - This species’ range includes the Mediterranean and outposts in the Atlantic such as the Canary Islands. However, its distribution does not cover the UK or English Channel (BirdLife International, 2018);
• Montagu’s Harrier – It is an extremely rare breeding bird in the UK, and its status is precarious. Each pair needs special protection. It seems increasingly to be nesting on arable farmland rather than on marshes. It is a summer visitor, and migrates to Africa to spend the winter ( RSPB, 2018);
• Smew - The distribution of this species mainly covers central and eastern parts of Europe. It can be found in southern UK breeding and feeding on inland fresh waterbodies (BirdLife International, 2018). This species is on the ‘Amber’ list and is considered to be of ‘Least Concern’ (BirdLife International, 2018; RSPB, 2018). It migrates overwinter in small numbers from Scandinavia and Russia and on occasion from Holland and Denmark to escape freezing weather there ( RSPB, 2018). Their flight paths are, therefore, unlikely to overlap with the Plan area (or AoS or DPO areas); and
• White tailed Eagle - This rare breeding bird is on the ‘Red’ list and was made extinct in the UK during the early twentieth century. The present population is confined to the east coast of Scotland where a reintroduction programme is taking place ( RSPB, 2018).

4.4.8 Based on the above outline review of their distribution and behaviour, there is not expected to be any LSE on these species from the draft Plan. Most of the species are unlikely to overlap with the effects brought about by the Plan and any ‘outlier’ species are anticipated to only be present in low numbers. Furthermore, by adopting the established broad screening process, as has been done for past plan-level HRAs, the HRA process will ensure that there are no adverse effects on a full range of bird species exhibiting a full range of at sea movements and foraging behaviours (i.e. surface feeders, divers, nocturnal, crepuscular ^[10] , long distance, coastal and offshore). This position will need to be reviewed at the screening and assessment stages of the HRA and will be subject to ongoing consideration and consultation with stakeholders.

4.4.9 To summarise the approach described above, the following iterative series of steps encompass the proposed screening methods for the bird interest feature group:

• Step 1: Identify the best understanding about possible cable alignments and landfall positions to make assumptions and, if possible, identify ‘areas of search’ for these locations;
• Step 2: Screen out any bird interest features for which there will be no LSE on the basis that there is definitely no impact pathway (e.g. where they are confined to inland terrestrial habitats and do not forage in coastal or offshore waters);
• Step 3: Screen in, following literature review, European/Ramsar sites that support qualifying bird interest features that forage over distances >100 km and could potentially feed within the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls. This will screen in some European/Ramsar sites that support these species but lie outside the 100 km boundary zone (and have not previously been identified in the pre-screening review). Non- UK sites will not be considered in this case because there is not expected to be any additional effect to qualifying birds species from other Member States;
• Step 4: Screen out any European/Ramsar sites supporting long distance foraging qualifying bird species that have a landmass greater than 50 km between them and the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls.
• Step 5: Update the screening Table A3 in Appendix A (see Step 7 for habitat interest features in Section 4.3) to indicate the European/Ramsar sites and supporting bird interest features that have been screened in or out of the assessment. Update the accompanying maps of screened in European/Ramsar sites within and adjacent to the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 6: Identify any plan-level mitigation measures that can be applied to ensure that there is no LSE on the screened in European/Ramsar sites and their qualifying interest features and, where possible, screen such features or sites out on this basis; and
• Step 7: Update the screening table and maps with the final list of screened in European/Ramsar sites and qualifying interest features.

4.5 Marine Mammals

4.5.1 The screening methods for this interest feature group need to consider the potential LSE from both direct and indirect sources of change. For this HRA it will be necessary to consider the effects on grey seal ( Halichoerus grypus), common seal ( Phoca vitulina), bottlenose dolphin ( Tursiops truncatus) and harbour porpoise ( Phocoena phocoena). These are the four species which are qualifying interest features of UK SACs.

4.5.2 A 100 km buffer has been used for pinnipeds in the majority of past plan-level HRAs (e.g. ABPmer, 2013; 2014; 2017; MMO, 2013; 2015). The HRA for The Crown Estate’s Offshore Floating Wind Plan ( AMEC, 2014), agreed in consultation with SNH to use a 50 km screening buffer for common seal and a 100 km buffer for grey seal. The ISLES Spatial Plan HRA also applied a buffer of 50 km on account that the impacts from marine cable infrastructure on foraging and migrating marine mammals would be temporary and most likely associated with elevated underwater noise during construction ( AECOM and ABPmer, 2015).

4.5.3 For the draft Plan HRA, a 100 km buffer for both seal species is considered the most objective and auditable screening approach because it defines the main foraging areas of both species. No additional sites supporting seal populations will be screened in beyond the 100 km buffer area. The distance over which these species move from their breeding and haul out sites is better understood than for cetacean species. Harbour seals primarily stay within 50 km of the coastline and within 100 km from their haul out sites (Jones et al., 2015; Vincent et al., 2017). Grey seals can travel over 100 km between haul out sites, with foraging trips lasting between 1 and 30 days. Tracking of individual seals has shown that although they can travel up to several hundred kilometres offshore, most foraging generally occurs within 100 km of a haul out site (Jones et al., 2015; SCOS, 2016). Therefore, movements over 100 km are not considered sufficiently frequent to warrant screening in more distant locations.

4.5.4 Bottlenose dolphins migrate and forage over much larger distances than seals and it is likely to be necessary to extend the assessment beyond the 100 km buffer to screen in more distant European/Ramsar sites. All European/Ramsar sites with qualifying bottlenose dolphin interest features that lie within the appropriate MUs defined for this species by the UK Inter-Agency Marine Mammal Working Group ( IAMMWG, 2015) and in which the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls are located in will be screened into the assessment (Figure 10). Non- UK sites will also be screened in where they lie within these relevant MUs. This follows the approach that was applied in the national plan-level HRA for The Crown Estate’s Wave and Tidal Further Leasing plan that includes the area covered by the draft Plan (ABPmer, 2014).

Figure 10: Bottlenose dolphin Management Units

Source: UK Inter Agency Marine Mammal Working Group ( IAMMWG, 2015).

4.5.5 In general harbour porpoise is wide ranging and it is known, for instance, from tagging work that individuals move several hundred kilometres from the Skagerrak across the North Sea (Teilmann et al., 2008). The same approach that has been proposed for bottlenose dolphin is considered appropriate for harbour porpoise. All European/Ramsar sites with qualifying harbour porpoise interest features that lie within the appropriate MUs defined for this species by the UK Inter-Agency Marine Mammal Working Group ( IAMMWG, 2015) and in which the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls are located in will be screened into the assessment (Figure 11). Non- UK sites will also be screened in where they lie within these relevant MUs. This follows the approach that was applied in the national plan-level HRA for The Crown Estate’s Wave and Tidal Further Leasing plan that includes the area covered by the draft Plan (ABPmer, 2014).

Figure 11: Harbour porpoise Management Units

Source: UK Inter Agency Marine Mammal Working Group ( IAMMWG, 2015).

4.5.6 To summarise the approach described above, the following iterative series of steps encompass the proposed screening methods for the marine mammal interest feature group:

• Step 1: Identify the best understanding about possible cable alignments and landfall positions to make assumptions and, if possible, identify ‘areas of search’ for these locations;
• Step 2: Screen in, following literature review, all European/Ramsar sites that have qualifying common or grey seal interest features that lie within 100 km of the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls as this zone encompasses the main area of potential foraging by seals;
• Step 3: Screen in, following literature review, all UK and non- UK European/Ramsar sites with qualifying bottlenose dolphin interest features that lie within the appropriate MUs defined for this species by the UK Inter-Agency Marine Mammal Working Group ( IAMMWG, 2015) and in which the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls are located in;
• Step 4: Screen in all UK and non- UK European/Ramsar sites with qualifying harbour porpoise interest features that lie within the appropriate MUs defined for this species by the UK Inter-Agency Marine Mammal Working Group ( IAMMWG, 2015) and in which the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls are located in;
• Step 3: Update the screening Table A3 in Appendix A (see Step 7 for habitat interest features in Section 4.3) to indicate the European/Ramsar sites and supporting marine mammal interest features that have been screened in or out of the assessment. Update the accompanying maps of screened in European/Ramsar sites within and adjacent to the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 4: Identify any plan-level mitigation measures that can be applied to ensure that there is no LSE on the screened in European/Ramsar sites and their qualifying interest features and, where possible, screen such features or sites out on this basis; and
• Step 5: Update the screening table and maps with the final list of screened in European/Ramsar sites and qualifying interest features.

4.6 Migratory Fish and Freshwater Pearl Mussel

4.6.1 The screening methods for this interest feature group need to consider the potential LSE from both direct and indirect sources of change. Anadromous fish species (i.e. those which live mainly at sea but spawn in freshwater) that could be affected by the draft Plan include Atlantic salmon, allis shad, twaite shad, sea lampreys and river lamprey. In addition freshwater pearl mussel will be susceptible indirectly because, while they are sessile species living in rivers, they share a life-history stage with migratory salmonids (Atlantic salmon and sea trout). Other migratory fish species that are not listed in Annex 1 of the Habitats Directive but form part of the qualifying criteria of Ramsar sites include the European eel, the European smelt and sea trout. Consideration should also be given to components (i.e. sub-features) of individual qualifying interest features within marine SACs (e.g. the European smelt is a fish of conservation concern listed as a typical species of habitat features within the Forth of Tay and Eden SAC).

While there is a recognition that gaps in understanding clearly remain about how fish migrate around UK waters, based on the available evidence (e.g. Malcolm et al., 2010; ERI, 2012; Guerin et al., 2014), the coastal regions of the UK were divided into seven broad regions by ABPmer (2014) (Figure 12). The West region covers the Bristol Channel, Celtic Sea, Irish Sea, Firth of Clyde and Strangford Lough. The North West region includes waters comprising the western part of Scotland. The North region covers the waters of northern Scotland. The Shetland region comprises the waters around the Shetland Island. The North East region covers the waters of eastern Scotland. The East region comprises the eastern coast of England and the South region spans the waters of the English Channel and western approaches.

Figure 12: Location and extent of coastal regions for screening fish qualifying interest features

Source: ABPmer (2014).

4.6.2 Based on the expected primary directions of fish migration, European/Ramsar sites along the UK coast, including estuaries and rivers, within the ‘West’, ‘North West’, ‘North’, ‘Shetland’ and ‘North East’ regions that support migratory fish and freshwater pearl mussel interest features will be screened into the assessment. This is because migratory fish are likely to enter these regions from either the Southwestern Approaches or the north and may pass through the draft Plan area (or AoS or DPO areas) to get to other regions.

4.6.3 To summarise the approach described above, the following iterative series of steps encompass the proposed screening methods for the migratory fish and freshwater pearl mussel interest feature group:

• Step 1: Identify the best understanding about possible cable alignments and landfall positions to make assumptions and, if possible, identify ‘areas of search’ for these locations;
• Step 2: Screen in, following literature review, all European/Ramsar sites supporting migratory fish and/or freshwater pearl mussel interest features along the UK coast, including estuaries and rivers, within the ‘West’, ‘North West’, ‘North’, ‘Shetland’ and ‘North East’ regions as defined by ABPmer (2014);
• Step 3: Update the screening Table A3 in Appendix A (see Step 7 for habitat interest features in Section 4.3) to indicate the European/Ramsar sites and supporting migratory fish and/or freshwater pearl mussel interest features that have been screened in or out of the assessment. Update the accompanying maps of screened in European/Ramsar sites within and adjacent to the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 4: Identify any plan-level mitigation measures that can be applied to ensure that there is no LSE on the screened in European/Ramsar sites and their qualifying interest features and, where possible, screen such features or sites out on this basis.
• Step 5: Update the screening table and maps with the final list of screened in European/Ramsar sites and qualifying interest features.

4.7 Otter

4.7.1 The screening methods for this interest feature group need to consider the potential LSE from both direct and indirect sources of change. The distances offshore that foraging occurs are unclear but are unlikely to be beyond water depths of greater than 10 m (the depth at which they are identified as being at risk of entanglement in pots/creels). Also while otter can move large distances along riverine habitats (some are known to use 20 km or more of river habitat), they tend to be very territorial. The guidance on undertaking surveys to assess impacts upon this species ( SNH, 2018) suggests that distances of 200-250 m are appropriate.

4.7.2 Based on past advice from SNH and previous plan-level HRA approaches (e.g. ABPmer, 2017), 10 km represents an appropriate distance beyond which a plan or project would be unlikely to have a significant effect. This 10 km buffer will be applied around the boundary of the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls. Any European/Ramsar sites (either coastal or inland) that support otter beyond this buffer will be screened out of the assessment (i.e. removed from the pre-screening Table A3 in Appendix A).

4.7.3 To summarise the approach described above, the following iterative series of steps encompass the proposed screening methods for the otter interest feature group:

• Step 1: Identify the best understanding about possible cable alignments and landfall positions to make assumptions and, if possible, identify ‘areas of search’ for these locations;
• Step 2: Screen out (i.e. remove from the pre-screening list) all European/Ramsar sites that have qualifying otter interest features beyond 10 km from the boundaries of the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 3: Update the screening Table A3 in Appendix A (see Step 7 for habitat interest features in Section 4.3) to indicate the European/Ramsar sites and supporting otter interest features that have been screened in or out of the assessment. Update the accompanying maps of screened in European/Ramsar sites within and adjacent to the Plan area (or AoS or DPO areas) and any defined areas of search for cable alignments and landfalls;
• Step 4: Identify any plan-level mitigation measures that can be applied to ensure that there is no LSE on the screened in European/Ramsar sites and their qualifying interest features and, where possible, screen such features or sites out on this basis; and
• Step 5: Update the screening table and maps with the final list of screened in European/Ramsar sites and qualifying interest features.

4.8 Bats

4.8.1 The screening methods for this interest feature group need to consider the potential LSE from both direct and indirect sources of change. There are 15 species of bat listed in Annex I of the Habitats Directive, of which none are an interest feature of European/Ramsar sites that have been initially screened into the assessment (see Table A3, Appendix A).

4.8.2 Bats are terrestrial species and it was previously considered unlikely that they migrate across large areas of sea, and that they did not forage within coastal habitats. Research carried out by BSG Ecology (2014) observed bats travelling offshore and suggested seasonal movements, as well as hibernating and roosting behaviour, occur in coastal regions. On this basis, recent plan-level HRAs have screened in any European/Ramsar sites with bat interest features occurring within 50 km of the plan area (e.g. MMO, 2015).

4.8.3 Given that no bat interest features have been identified within the wider pre-screening buffer applied for the draft Plan, no bat interest features will be screened into the assessment by using a 50 km buffer at the screening stage. There will therefore be no bat interest features screened into the HRA for the draft Plan and these will not be considered further.

4.9 Assessment Methodology

4.9.1 The assessment will build on the screening process by considering the particular environmental pressures and changes that give rise to a LSE of an interest feature and then providing a generic assessment of the impact on European/Ramsar site integrity having regard to the site’s conservation objectives.

4.9.2 A standardised iterative assessment process is proposed to assess the impact on each of the key interest feature groups of habitats and species. The individual steps in this process are as follows:

• Step 1: Impact pathways review - Identification of the impact pathways that are relevant for offshore wind development;
• Step 2: Identify activities to which features are sensitive - A review of the activities involved in offshore wind development, and the environmental changes arising, which could have an impact on European/Ramsar sites or interest features via the identified impact pathways;
• Step 3: Activity-based screening of European/Ramsar Sites – Identification (screening) of those European/Ramsar sites and their relevant interest features for which there is a LSE, or for which a LSE cannot be excluded, from the activities and impact pathways;
• Step 4: Detailed pathway-feature sensitivity review - A review of the sensitivities of the relevant interest features to the identified impact pathways and activities; and
• Step 5: Assessment of the potential effects on European/Ramsar sites - Assessment of impacts via each of the activities associated with offshore wind development both alone and in-combination with other extant plans or projects. This is followed by the identification of available mitigation measures for each identified impact pathway and the identification, where required, of additional mitigation measures which ensure that these activities have no AEOI.

4.9.3 Based on the approaches adopted for previous plan-level HRA work, the results of this phased assessment work will be mainly presented in a series of tables/matrices.

4.9.4 In keeping with the approach adopted for past plan-level HRAs, no European/Ramsar sites or features will be removed/deleted from the screening tables. Instead, distinction will be made between the sites which are screened in or out of the assessment process. This will ensure that the approach and conclusions of this impact assessment process are fully auditable in the future.

4.10 Step 1: Impact Pathways Review

4.10.1 The first step of the assessment involves identifying and understanding the pathways by which a proposed activity might have an effect on European/Ramsar sites and their associated interest features. This has initially been undertaken as part of pre-screening and will be reviewed and updated if necessary in the assessment stage of the HRA (see Section 3.2 and Table A1 in Appendix A).

4.11 Step 2: Identify Activities to Which Features are Sensitive

4.11.1 Having identified the relevant generic impact pathways in Step 1, the next stage in the analysis will be to review the individual activities that might affect European/Ramsar sites and their interest features. This has initially been undertaken as part of pre-screening and will be reviewed and updated if necessary in the assessment stage of the HRA (see Section 3.2 and Table A2 in Appendix A).

4.12 Step 3: Activity Based Screening of European/Ramsar Sites

4.12.1 The preceding screening stage of the HRA described in Sections 4.2 to 4.8 will have identified the full list of European/Ramsar sites that could potentially be affected by the draft Plan in advance of a review of the specific activities that need to be assessed. For Step 3 of the assessment, there will be a need to consider which of the European/Ramsar sites will be affected by activities associated with offshore wind development.

4.12.2 As a first stage of this analysis, an updated review of the status of European/Ramsar sites will be undertaken to identify any new sites that have been identified since the completion of the screening. Once a full final list of sites has been produced, an updated list of ‘screened in’ sites and features will be created to identify those for which there is considered to be a potential LSE from the range of activities that could result from the implementation of the Plan.

4.12.3 As mentioned above, no European/Ramsar sites or features will be removed from these tables because it is important that they continue to provide a full and transparent audit of the assessment process. In addition to presenting these comprehensive lists of all the sites and their features, a final overall summary screening schedule will be created which only includes those European/Ramsar sites, and their relevant interest features, which could potentially be affected (i.e. subject to a possible LSE) by the draft Plan.

4.12.4 For this work, as with all other elements of the assessment, a precautionary approach will be adopted and European/Ramsar sites will only be screened out where there is certainty that there will be no LSE.

4.13 Step 4: Detailed Pathway Feature Sensitivity Review

4.13.1 A detailed review of the sensitivities of the interest features (i.e. their intolerance from damage or death from an external factor) will then be undertaken. This sensitivity review will relate to the relevant project-level activities associated with the draft Plan that have been screened into the assessment. The results will be presented in a series of ‘pathway-sensitivity’ tables for each key interest feature group as described below.

4.13.2 It should be emphasised that only the interest feature’s level of sensitivity (low, medium or high) to each impact pathway will be reviewed and not the level of risk/exposure or vulnerability ^[11] . Based on previous plan-level HRAs there is likely to be little information available on the exposure to change from activities resulting from the draft Plan and, therefore, taking a precautionary approach it is considered appropriate for the assessment to base its impact consideration on sensitivities only and assume, that an exposure will occur.

4.13.3 The judgements that are made here about sensitivity will be based on the ecology of interest features as well as on details about the activities and changes arising from the Plan. While there are variations in sensitivity, and differences in the level of scientific certainty associated with determining these levels, a precautionary approach will be followed for this assessment, as required under the Habitats Regulations, and all potential impact pathways will be addressed irrespective of the varying levels of sensitivity. Ongoing research work will help to inform future judgements about these sensitivities and also where individual projects are taken forward following the implementation of the Plan then the exposure levels and hence the vulnerabilities of interest features rather than just the sensitivities will be understood.

4.13.4 The ‘pathway-sensitivity’ tables will be structured according to the standard Natura 2000 sensitivity categories (as listed in Section 3.2). The tables will indicate the phases in the implementation process for individual projects at which the impact pathways are relevant (i.e. survey, construction, operation or decommissioning) and the sensitivity levels (high, medium or low) associated with each of these phases. An impact pathway reference number will also be included in the table that relates to the generic impact pathways that will have been identified in Step 1 of the assessment (see Section 3.2). This number will facilitate comparisons within and between tables and enable any party interrogating these details (e.g. regulator, stakeholder or developer) to readily cross-refer between tabular outputs.

4.14 Step 5: Assessment of Effects on European/Ramsar Sites

4.14.1 The final step will be to assess the impacts that will or could occur via each of the identified pathways against the European/Ramsar site’s conservation objectives. The conservation objectives will be identified from online sources such as the JNCC, SNH and EU websites, and through consultation with both SNH and JNCC.

4.14.2 During the previous HRAs for the Draft Plan for Offshore Wind Energy in Scottish Waters and the Draft Sectoral Marine Plans for Offshore Renewable Energy (ABPmer, 2011a; 2017) it was agreed with the overseeing PSG that it was not possible to identify and review the individual and specific objectives for each European/Ramsar site because of the large number of sites screened into the assessment. Therefore a series of typical and generic objectives were identified which could be applied across all European/Ramsar sites. This same approach is proposed for the draft Plan HRA.

4.14.3 Based on these generic conservation objectives, the potential effects on the European/Ramsar sites via each of the relevant impact pathways will be reviewed. An initial view will then be taken about the effect on site integrity of the draft Plan both alone and in-combination with other extant plans or projects, in advance of the formal judgement that is to be made by Marine Scotland, in consultation with SNH, as part of Stage 12 of the HRA (see Figure 4).

4.14.4 The views on the effects on site integrity will be based on current scientific understanding and the proposed manner in which the draft Plan is to be implemented. This judgement will be made in the context of any ‘initial’ plan-level mitigation measures that have been identified as an integral strategic component of the Plan to avoid or reduce impacts.

4.14.5 Where the information indicates that there could be an AEOI as a result of the draft Plan, then ‘additional’ plan-level mitigation measures will be identified to avoid such an effect in fulfilment of Stage 9 of the HRA (Figure 4). The Plan will be re-assessed following the application of these mitigation measures to seek to further avoid an AEOI.

4.14.6 Given the inherent uncertainties associated with the draft Plan (see Section 2.5), there will be a need for additional plan-level mitigation measures. One such measure will include the requirement for project-level HRA. This is based on a recognition that, as a matter of law, any new project developed under the draft Plan will be required to undergo a project-level HRA and to produce an AA wherever the possibility of LSE on a European/Ramsar site cannot be excluded. Each individual project will need to review the baseline conditions and undertake work in a manner that does not have an AEOI. The information provided within this HRA will therefore include information that gives direction to future project level AAs.

4.14.7 The requirement for project-level HRA, however, will not provide full assurances of no AEOI, particularly when considering uncertainties associated with in-combination effects (Section 4.15). Therefore, a second additional plan-level mitigation measure will be needed to be assured that all evidence gaps and impact pathways will be addressed. This additional measure will be a clear process for the implementation of the Plan. In particular, the process needs to involve a phased and iterative approach to offshore wind projects such that their implementation is phased and linked to ongoing monitoring with the findings from such monitoring feeding back into the next phases of work. The adoption of what is termed an ‘Iterative Plan Review’ ( IPR) process is in keeping with recommendations made for the previous draft Plans for Offshore Renewable Energy (e.g. ABPmer, 2011; 2017) and also, for the East and the South Marine Plans in England ( MMO, 2013; 2015).

4.14.8 In addition to these additional plan-level mitigation measures, it is recognised that for individual offshore wind development projects a range of such mitigation measures are available to help reduce or offset ecological effects where needed. Lists of such measures have been developed during previous strategic assessments (e.g. ABPmer, 2011a; 2017; Entec, 2011). An overall list of measures from these sources will be assembled as part of the assessment to provide a central ‘project-level mitigation options’ data table. The mitigation measures will be compared against the impact pathways to indicate which measures address which impacts.

4.14.9 While this list will demonstrate the range of project-level mitigation measures that are available, they do not, by themselves, provide further certainty that any European/Ramsar site or interest features will not be affected. This is because they are not a formal requirement of the draft Plan and they are too generic in nature to be assured that there will be no adverse effects as a result of their application. However, they will be brought together for this HRA in order to provide a basis for understanding the measures that will or may be required for projects in the future.

4.14.10 The outputs of this assessment stage, including proposed mitigation measures, will be documented in an Appropriate Assessment Information Report. This report will provide a draft record of the HRA (Stage 10 of the HRA) to inform subsequent consultations and the preparation of a final AA (Stages 11 to 13 of the HRA).

4.15 In-combination Assessment

4.15.1 The Habitats Regulations require that, in determining whether a plan or project is likely to have a significant effect on a European/Ramsar site, the plan or project should be considered both alone and in-combination with other plans or projects.

4.15.2 The in-combination assessment is a challenging element of plan-level HRA work. There is a need to undertake a full review of extant and relevant plans and projects and to ensure that the assessment findings fully consider in-combination effects or at least the uncertainties associated with assessing such effects. It is also advisable that the approaches and solutions identified in past sectoral marine plan HRAs are reviewed. It is likely that the process of plan implementation will need to be framed (e.g. using an Iterative Plan Review ( IPR) process) to ensure no in-combination effects in the future.