Changes in fish and shellfish communities affecting prey availability
1329 As outlined in paragraph 1051 et seq., there is potential for changes to prey availability for grey seals due to potential impacts on prey species during operation and maintenance of the Proposed Development. These impacts include temporary subtidal habitat loss/disturbance, long-term subtidal habitat loss, increased SSC and associated sediment deposition, EMF from subsea electrical cabling and colonisation of foundations, scour protection and cable protection.
1330 Potential temporary habitat loss/disturbance during operation and maintenance equates to a smaller area than that affected during construction (up to 989,000 m2 which equates to 0.08% of the fish and shellfish ecology area, compared with 9.7% during the construction phase; volume 2, chapter 9 of the Offshore EIA Report). Operation and maintenance activities will occur periodically over the full lifetime of the project (estimated to be 35 years). As described in paragraph 1011, only a small proportion of the maximum footprint of habitat loss/disturbance may occur at any one time, with areas starting to recover immediately after cessation of maintenance activities. It is expected that grey seal could come back to forage within areas previously disturbed after cessation of works and therefore their distribution and connectivity with important habitats within and outside the site is unlikely to be impaired in long term.
1331 Increased SSC could occur as a result of repair or remedial burial activities during the operation and maintenance phase. The maintenance activities will be undertaken at intervals over the 35 years operation and maintenance phase. Any suspended sediments and associated deposition are expected to l be of the same magnitude, or lower as for construction. Therefore, the availability of suitable food supply for grey seal is not expected to be impaired as a result of increase in SSC and associated deposition.
1332 The presence and operation of inter-array, interconnector and offshore export cables will result in emissions of localised electrical and magnetic fields, which could potentially affect the sensory mechanisms of some species of fish and shellfish. The range over which species can detect EMF will be very localised to within a few centimetres of the buried cable, with rapid decay of the EMF with increasing distance Considering the above, adverse effects on grey seal as a result of changes in prey availability due to EMF are highly unlikely.
1333 Although there will be long term loss of habitat due to the presence of infrastructure associated with the Proposed Development, it is also anticipated that artificial structures will provide hard settlement opportunities and provide a valuable food source for fish. As discussed in paragraph 1021 et seq., evidence increasingly suggests that foraging opportunities for marine mammals, including grey seals, are increased around offshore wind farm structures.
1334 As described in paragraph 1023 et seq., while grey seal has a relatively selective diet of predominantly flatfish and sandeel, the species has an observed wide ranging foraging ability within the region. The fish and shellfish communities found within the fish and shellfish ecology study area (see volume 2, chapter 9 of the Offshore EIA Report) are characteristic of the fish and shellfish assemblages in the northern North Sea. As the impacts of operation and maintenance works will be highly localised, temporary in nature and restricted to the boundaries of the Proposed Development, only a small area will ever be affected compared with the available foraging habitat for grey seals in the northern North Sea. It is therefore reasonable to assume that, due to the highly mobile nature of grey seals, there will be similar and suitable prey resources available in the wider area. Given that the habitat is likely to return to the state that existed before the activity or event which caused change, it is highly unlikely that maintenance works resulting in habitat loss/disturbance will influence grey seal population trajectory in the long-term.
1335 Significant adverse effects on the qualifying Annex II marine mammal feature grey seal of the Isle of May SAC are not predicted to occur as a result of changes in fish and shellfish communities affecting prey availability during operation and maintenance phase (i.e. in relation to maintaining the cover and abundance of preferred food items required by the species).
Conclusion
1336 The assessment has concluded that distribution of the species within the site and the distribution and extent of habitats supporting the species is unlikely to be impaired in long term. It is expected that grey seal population would be able to tolerate the effect of changes in fish and shellfish communities without any impact on reproduction and survival rates and it will not influence the population of the species as a viable component of the site. As such, the conservation objectives for Annex II species, grey seal, will not be undermined.
1337 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC from changes in fish and shellfish communities affecting prey availability with respect to the operation of the Proposed Development acting alone.
Effects in-combination
1338 An assessment of in-combination effects upon the qualifying Annex II marine mammal species of the Isle of May SAC arising from each identified impact is provided below.
1339 The potential to experience injury in terms of PTS by marine mammal receptors as a result of underwater noise due to piling and vessel use/other activities would be expected to be largely localised within the boundaries of the respective projects (assuming similar ranges of effect as presented for the Proposed Development). It is also anticipated that standard offshore wind industry construction methods (which include soft starts and visual and acoustic monitoring of marine mammals as standard) will be applied, thereby reducing the magnitude of the impact with respect to auditory injury occurring in marine mammals. Therefore, there is no potential for significant in-combination impacts for injury from elevated underwater noise during pilling and vessel use/other activities and the in-combination assessment focuses on disturbance only.
Assessment of in-combination effects during construction and decommissioning
Injury and disturbance from elevated underwater noise during piling
Tier 2
1341 Both projects screened in for the in-combination assessment for grey seal (paragraph 1340) are located within a behavioural disturbance footprint of the Proposed Development. The outermost contour of 135 dB represents the edge of the area within which grey seal may experience behavioural disturbance during concurrent piling at 4,000kJ hammer energy at Proposed Development. The assessment presented in the Inch Cape EIA (Inch Cape Offshore Limited, 2018) and original Seagreen EIA (Seagreen Wind Energy Ltd, 2012) estimated that 1,236 and 465 grey seals could experience disturbance during piling at respective projects. The duration of any disturbance at Seagreen 1A Project will be relatively short and is currently planned to take place between April and July 2023 (i.e. more than two years before planning commencement of piling at Proposed Development (Seagreen Wind Energy Ltd, 2020)).
1342 As the construction of Inch Cape and Seagreen 1A Project will be completed prior to commencement of piling at the Proposed Development, the potential for simultaneous piling, and therefore additive in-combination effects, with Proposed Development is highly unlikely. Population modelling was carried out to explore the potential of cumulative effects as a result of disturbance during piling to affect the population trajectory over time. Population modelling considered Seagreen 1A Project and Inch Cape Offshore Wind Farm and respective numbers of animals potentially impacted against the wider MU population (see volume 3, appendix 10.4 of the Offshore EIA Report for methods applied in the model). Results of the cumulative iPCoD modelling for grey seal showed that no impacts are predicted on the wider population resulting from disturbance due to cumulative piling events, with the mean impacted population the same as the mean unimpacted population at the 25 year time point. Therefore, it was considered that there is no potential for the long-term effects on this species within wider population as a result of cumulative piling at proposed Development and respective projects (see volume 3, appendix 10.4 of the Offshore EIA Report for more details).
1343 In temporal terms, there is a potential that animals in the vicinity of the Firth of Forth and Tay will experience disturbance consecutively as piling at different projects progresses. Grey seals are known to modify their behaviour in a response to piling noise but come back to pre-piling behaviour immediately after pile-driving ceased (Aarts et al., 2018). Therefore, it is highly unlikely that the reproductive and recruitment capability of the species will be affected.
1344 As described in paragraph 1133, during piling at Proposed Development, the behavioural disturbance contours will not reach the coast and will not overlap with Isle of May Coast SAC (in volume 2, chapter 10 of the Offshore EIA Report). As there will be no overlap of piling phases with either of the projects, grey seals present in habitats within the SAC, are highly unlikely to experience disturbance. As such, piling activities are highly unlikely to disrupt normal behaviours of grey seals or adversely affect the maintenance of supporting habitats.
1345 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of underwater noise during piling during construction with respect to the Proposed Development acting in-combination with Tier 2 projects.
Injury and disturbance from elevated underwater noise during site investigation surveys
Tier 2
1347 The construction as well as operation and maintenance phases of Eastern Link 1 and Eastern Link 2, located respectively 14 km and 28 km from the Proposed Development array area, will overlap with the construction phase of the Proposed Development. Based on the Environmental Appraisals for both projects, the only underwater sound noise sources that are within hearing range of marine mammals and have potential to have an effect, are the operation of the USBL and the SBP (AECOM, 2022a; 2022b). The disturbance ranges for grey seal were estimated as 63 m for USBL and 4,642 m for SBP. The detailed assessment of impacts as a result of underwater noise during the operation of SBP for both projects was presented for installation phase only. There are no disturbance ranges presented for the USBL for the Proposed Development alone but the disturbance range for SBP has been assessed as 2,045 m. Nevertheless, the assessment presented in paragraph 955 945et seq. is based on the maximum disturbance range all geophysical activities, which for the Proposed Development was predicted for vibro-coring as 7,459 m. Using the published at-sea density maps (Carter et al., 2020), the maximum number of grey seals estimated to be disturbed was 210 grey seals (3.6% of the Isle of May SAC population). However, this was shown to be highly precautionary when compared with estimates of the number of grey seal using site-specific densities derived from the Proposed Development aerial digital survey data (see paragraph 1283 for comparison).
1348 Based on the distance from the Proposed Development to both projects, the overlap of disturbance ranges is highly unlikely. The potential for an overlap exist only for site-investigation surveys taking place in the northern part of the Eastern Link 1, close to the Proposed Development export cable corridor and landfall ( Figure 13.3 Open ▸ ). Based on the telemetry tracks, the areas close to the landfall are not regularly visited by individuals from this SAC and although the connectivity between these areas and grey seals from the Isle of May SAC cannot be discounted, the behavioural disturbance could potentially affect a negligible proportion of the population. It needs to be noted that site investigation survey equipment will not be operating continuously, it will be used when required for investigations of particular areas of the seabed where additional information is required to inform the construction.
1349 With foraging ranges of up to 100 km, grey seals may be sensitive to a behavioural disturbance during the site-investigation surveys as they move between haul-outs and key foraging areas. During the breeding or moulting season many seals tend to spend more time on land, unaffected by underwater sound. Nevertheless, the availability of food is vital to offspring survival and female fitness (see paragraph 1085 et seq for more details). As advised by NatureScot ( Table 8.1 Open ▸ ), grey seal in Scotland tend to stay within 20 km of the breeding colony during the breeding season. Given the distance from Eastern Link 1 and Eastern Link 2 to the SAC (approximately 26 and 90 km, respectively), operation of the survey equipment is unlikely to disturb animals from this SAC within their main foraging grounds during the breeding season. Disturbance ranges during vibro-coring at Proposed Development have the potential to slightly overlap with foraging ranges of grey seal from the Isle of May SAC, however, given that alternative areas for foraging are widely available, the disturbance to seals is not considered likely to have a significant impact on food availability (see paragraph 1365 et seq. for the in-combination assessment of impacts as a result of changes in prey availability) and therefore on fitness and survival of the grey seal population. Given that geophysical surveys will occur intermittently and are short in duration, grey seals are anticipated to return to foraging grounds when the impact has ceased and therefore the connectivity with important habitats within and outside the site is unlikely to be impaired.
1350 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of site investigation surveys during the construction phase with respect to the Proposed Development acting in-combination with Tier 2 projects.
Injury and disturbance from elevated underwater noise during UXO clearance
Tier 2
1351 There is potential for in-combination effects from injury and/or disturbance from underwater noise during UXO clearance to grey seal from the Isle of May SAC during the construction phase of the Proposed Development with activities associated with the Inch Cape Offshore Wind Farm and Moray West Offshore Wind Farm.
1352 Projects screened in for this in-combination assessment are expected to involve similar construction activities to those described for the Proposed Development alone, including UXO clearance activities. It is anticipated that, for all projects, impacts associated with these activities will require additional assessment under EPS licensing, however such applications are not yet available in the public domain. The conclusions presented in volume 2, chapter 10 of the Offshore EIA Report demonstrated that the residual risk to grey seals, in terms of injury (PTS and TTS) as a result of UXO clearance activities at Proposed Development and respective projects would be low.
1353 For the Proposed Development alone, the maximum range across which grey seals have the potential to experience PTS due to high order detonation of 300 kg charge was assessed as approximately 2,085 m. PTS onset ranges for Inch Cape Offshore Wind Farm and Moray West Offshore Wind Farm are currently unknown, but for the purpose of this assessment we can assume that the maximum adverse scenario is no greater than assessed for the Proposed Development alone. Depending on the type of detonation and size of UXO, UXO clearance activities may have residual effects in respect to marine mammals and PTS injury. In November 2021, the UK government published a joint interim statement advising to use low noise alternatives to high order detonations where possible and it is anticipated that future developments will follow this guidance. However, due to a small inherent risk with these clearance methods that the UXO will detonate or deflagrate violently, accidental high order detonation can be expected as a maximum adverse scenario. Taking into account high order detonation of 300 kg charge and appropriate designed-in and secondary mitigation measures (paragraph 978 et seq.), there will be no residual risk of injury and therefore, it is highly unlikely that the reproductive and recruitment capability of the species will be affected.
1354 In terms of TTS, for the Proposed Development alone, the range across which grey seals have the potential to experience TTS due to high order detonation of a 300 kg charge was as approximately 6,430 m (see paragraph 971 et seq.). TTS onset ranges for Inch Cape Offshore Wind Farm and Moray West Offshore Wind Farm are currently unknown, but for the purpose of this assessment we can assume that the maximum adverse scenario is no greater than assessed for the Proposed Development alone. A spatial maximum adverse scenario would occur where UXO clearance activities occur concurrently at the respective projects considered in the in-combination assessment. This is however highly unlikely, as due to safety reasons the UXO clearance activities takes place before other construction activities commence, and both projects considered in the in-combination start their construction activities two years before commencement of construction at Proposed Development. Temporally however, sequential UXO clearance at respective projects could lead to a longer duration of effect. Since each clearance event results in no more than a one second ensonification event and since TTS is a recoverable injury, the potential for in-combination effects with respect to TTS is considered to be very limited. Therefore, in-combination effects caused by UXO clearance are considered unlikely to cause a change in reproduction and survival rates or alteration in the distribution of the population from Isle of May SAC. Given that effect of TTS is short in duration, connectivity with important habitats within and outside the site is also unlikely to be impaired.
1355 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of underwater noise during UXO clearance during the construction phase with respect to the Proposed Development acting in-combination with Tier 2 projects.
Injury and disturbance from elevated underwater noise during vessel use and other activities
Tier 2
1356 There is potential for in-combination effects from injury and/or disturbance from underwater noise due to vessel use and other activities to grey seal from the Isle of May SAC during the construction and decommissioning phase of the Proposed Development with activities associated with the following projects: Eyemouth, Inch Cape Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Eastern Link 1, Eastern Link 2, Neart na Gaoithe and Blyth Demo 2.
1357 Whilst there is no quantitative information available for noise disturbance ranges for offshore wind farms included in the in-combination assessment, it is anticipated that there will be a similar scale of effects with respect to noise effects as those described for Proposed Development alone (paragraph 988 et seq.). In terms of behavioural disturbance, the noise modelling predicted a maximum range of approximately 4 km for construction activities such as cable laying as well as activity of rock placement vessels (described in detail in volume 3, appendix 10.1 of the Offshore EIA Report) and therefore, disturbance effects are likely to occur cumulatively. The Isle of May SAC is located at the entrance to the Firth of Forth and there is a risk that vessels will pass next to the SAC on route to ports or harbours, including Grangemouth, Rosyth, Leith and Braefoot Bay (see volume 2, chapter 13 of the Offshore EIA Report). Additionally, due to the presence of offshore wind farms, such as Inch Cape, deviations from main commercial routes are anticipated, including the need to pass north of the Isle of May or alter course sharply once beyond the two special marks located east of the Isle of May. As previously discussed in paragraph 1109, seals exhibit avoidance behaviour or alert reactions when disturbed, as hauled out seals typically flush into the water which may be detrimental during pupping season. Therefore, increases in vessel movements next to the SAC between late September and January may pose a risk of affecting lactation and milk intake of pups, which can be detrimental to their condition and impact rearing success. It is however an industry standard that vessels follow a Code of Conduct, which include advice not to approach marine mammals and it is anticipated that operation and maintenance vessels at all relevant projects will follow these guidelines. Grey seals that live around the island all year are expected to tolerate presence of vessels, as boat tours to Isle of May SAC are very frequent between April and September each year. Therefore, in-combination effects caused by vessel use and other activities during operation and maintenance phase are considered unlikely to cause a change in reproduction and survival rates or alteration in the distribution of the population from Isle of May SAC.
1359 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of underwater noise during vessel use and other activities during the construction phase with respect to the Proposed Development acting in-combination with Tier 2 projects.
Tier 3
1362 Due to lack of project information at this stage, it is not possible to undertake full, quantitative assessment for this impact and therefore a qualitative assessment is provided. The maximum range over which potential disturbance may occur for the Proposed Development alone as a result of drilled piling and jet trenching, is predicted out to 1,900 m and 2,580 m, respectively. Cable installation activities assessed for the Proposed Development alone have the potential to disturb marine mammals out to 4,389 m. Given the location of the SAC with respect to the Proposed Development and Cambois connection, there is no potential for cumulative overlap of behavioural ZoI at respective projects and this designated site.
1363 Nevertheless, outside the SAC in offshore waters, construction activities could lead to a larger area of disturbance and larger number of animals disturbed within their foraging range compared to the Proposed Development alone if projects were to conduct construction activities over similar time periods. As described in paragraph 1216 et seq., it can be anticipated that grey seals from the Isle of May SAC demonstrate some degree of habituation to ship noises. Therefore, in-combination effects caused by vessel use and other activities are considered unlikely to cause a change in reproduction and survival rates or long-term alteration in the distribution of the population from the Isle of May SAC.
1364 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of underwater noise during vessel use and other activities during the construction phase with respect to the Proposed Development acting in-combination with Tier 3 projects.
Changes in fish and shellfish communities affecting prey availability
1366 The construction phases and/or operation and maintenance phases respective projects may lead to in-combination temporary subtidal habitat loss/disturbance. The total in-combination temporary subtidal habitat loss is 145,325,450 m2 (=145.3 km2), however this number is highly conservative as the temporal overlap in construction activities between projects will be small and therefore there will only be a small area of temporary habitat loss happening at any one time. The magnitude of long-term habitat loss caused by the presence of all structures on the seabed has been considered for the construction as well as operation and maintenance phases. The impacts have been assessed in-combination with Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, and Seagreen 1, Seagreen 1A Project and Seagreen 1A Export Cable Corridor, Eastern Link 1 and Eastern Links 2 and may lead to long term subtidal habitat loss of up to 15,014,156 m2 (=15.0 km2).
1367 An increase in SSC and associated sediment deposition as a result of the construction as well as operation of projects screened into the in-combination assessment may result in short-term avoidance of affected areas by fish and shellfish which may have an indirect effect on grey seals. Elevations in SSC are expected to be of short duration, returning to background levels relatively quickly. SSC are not expected to reach the concentrations required for an extended period for there to be any effect on fish and shellfish adult/larvae survival. Additionally, deposited sediments are expected to be removed quickly by the currents resulting in small amount of sediment being deposited. Given that the effect on spawning grounds of grey seal prey key resource (sandeel) are predicted to be limited as a result of increased SSC and associated sediment deposition (see paragraph 1227) and small temporal overlap of construction phases at respective projects, the availability of suitable food supply for grey seals is not expected to be impaired.
1368 OSP/Offshore convertor station platforms outlined in paragraph 1023 et seq., while grey seal has a relatively selective diet of predominantly flatfish and sandeel, the species can forage widely, sometimes covering extensive distances. Given that the impacts of temporary and long-term will be localised when compared to wider habitat available and largely restricted to the boundaries of the respective projects, only a fraction will be affected when compared to available foraging habitat for grey seals in the northern North Sea. Since the habitat is likely to return to the state that existed before the activity or event which caused change, the availability of suitable foraging grounds for grey seals is not expected to be impaired hence the population trajectory is unlikely to be affected in the long-term.
1369 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of changes in fish and shellfish communities affecting prey availability during construction and decommissioning with respect to the Proposed Development acting in-combination with Tier 2 projects.
Tier 3
1370 There is potential for in-combination effects from changes in fish and shellfish communities affecting prey availability to grey seal from Isle of May SAC during the construction and decommissioning phases of the Proposed Development with activities associated with the construction and operation of Cambois connection.
1371 The construction phase of Cambois connection may lead to in-combination temporary subtidal habitat loss/disturbance. The total in-combination temporary subtidal habitat loss/disturbance is 17,000,000 m2 (=17.0 km2), however this number is highly conservative as the temporal overlap in construction activities between projects will be small and therefore there will only be a small area of temporary habitat loss happening at any one time. The majority of this disturbance will not spatially overlap with the Proposed Development and where the overlap exist with the Proposed Development array area (previously impacted during the construction of the Proposed Development), it is expected to be highly localised and so the potential for repeat disturbance is considered low and unlikely to lead to an increase in the magnitude than predicted for the Proposed Development alone. The installation of Cambois connection can also result in a total area of long-term subtidal habitat loss of 306,000 m2.
1372 There is also a potential for in-combination effects associated with SSC and associated deposition. However, elevations in SSC during the construction phase will be of short duration, returning to background levels relatively quickly. SSC will not reach the concentrations required for an extended period for there to be any effect on fish and shellfish adult/larvae survival. Therefore, it is highly unlikely to have indirect impacts on grey seals from Isle of May SAC via changes to prey species.
1373 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of changes in fish and shellfish communities affecting prey availability during construction and decommissioning with respect to the Proposed Development acting in-combination with Tier 3 projects.
Assessment of in-combination effects during operation and maintenance
Injury and disturbance from elevated underwater noise during site investigation surveys
Tier 2
1374 There is potential for in-combination effects from injury and/or disturbance from underwater noise due to site investigation surveys to grey seal during the operation and maintenance phase of the Proposed Development with the operation and maintenance Eastern Link 1 and Eastern Link 2.
1375 The maximum design scenario for Proposed Development alone comprises of routine geophysical surveys estimated to occur every six months for first two years and annually thereafter. This equates to up to 37 surveys over the 35-year life cycle of Proposed Development ( Table 11.2 Open ▸ ). As presented in paragraph 1347, the detailed assessment of impacts on marine mammals as a result of underwater noise due to geophysical surveys during the operation and maintenance phase of the Eastern Link 1 and Eastern Link 2 is unavailable.
1376 An overview of potential impacts from as a result of behavioural disturbance due to elevated underwater noise during geophysical site investigation surveys is described in paragraph 1346 et seq. for the construction phase and has not been reiterated here for the operation and maintenance phase. The magnitude of the impact of underwater noise from geophysical surveys during operation and maintenance phase in combination with other projects considered in cumulative assessment could result in a negligible alteration to the distribution of grey seal in the short-term, however the overlap of disturbance ranges is unlikely. Given that geophysical surveys will occur intermittently over operation and maintenance phases of respective projects and are short in duration, grey seals are anticipated to return to foraging grounds when the impact has ceased and therefore the connectivity with important habitats within and outside the site is unlikely to be impaired.
1377 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of site investigation surveys during the operation and maintenance phase with respect to the Proposed Development acting in-combination with Tier 2 projects.
Injury and disturbance from elevated underwater noise during vessel use and other activities
Tier 2
1379 Vessels involved in the operation and maintenance of other wind farms will include a similar suite of vessels as those described for the Proposed Development alone (see paragraph 1044 et seq.), such as vessels used during routine inspections, repairs and replacement of equipment, major component replacement, painting or other coatings, removal of marine growth and replacement of access ladders. Given that the number of vessel round trips and their frequency is much lower for the operation and maintenance phases compared to construction phases of the respective projects, the magnitude of the impact for disturbance as a result of elevated underwater noise due to vessel use and other activities is expected to be less than that assessed for the construction phase. However, the duration of the effect will be longer (over the 35-year operating lifetime of the Proposed Development).
1380 During the operation and maintenance phase of the Proposed Development, the wind farms listed in paragraph 1378 will reach their decommissioning age before the Proposed Development reaches its decommissioning age in 2066. The environmental statements for respective projects predicted the number and type of vessels associated with decommissioning are expected to be, at worst, similar to construction. The Isle of May SAC is located at the entrance to the Firth of Forth and there is a risk that vessels will pass next to the SAC on route to ports or harbours, including Grangemouth, Rosyth, Leith and Braefoot Bay (see volume 2, chapter 13 of the Offshore EIA Report). Additionally, due to the presence of offshore wind farms, such as Inch Cape, deviations from main commercial routes are anticipated, including the need to pass north of the Isle of May or alter course sharply once beyond the two special marks located east of the Isle of May. As previously discussed in paragraph 1109, seals exhibit avoidance behaviour or alert reactions when disturbed, as hauled out seals typically flush into the water which may be detrimental during pupping season. Therefore, increases in vessel movements next to the SAC between late September and January may pose a risk of affected lactation and milk intake of pups, which can be detrimental to their condition and impact rearing success. It is however an industry standard that vessels follow a Code of Conduct, which include advice not to approach marine mammals and it is anticipated that vessels from all relevant projects will follow these guidelines. Grey seals that live around the island all year are expected to tolerate presence of vessels, as boat tours to Isle of May SAC are very frequent between April and September each year. Additionally, it can be expected that after more than ten years of construction activities taking place in the vicinity of Firth of Forth (i.e. Seagreen 1 construction activities commenced in 2021 and the operation and maintenance phase of Proposed Development is expected to start from 2033), marine mammals present in the area will demonstrate some degree of habituation to ship noises. Therefore, in-combination effects caused by vessel use and other activities during operation and maintenance phase are considered unlikely to cause a change in reproduction and survival rates or alteration in the distribution of the population from Isle of May SAC.
1381 As presented in volume 2, chapter 13 of the Offshore EIA Report, the commercial vessel numbers in the vicinity of the Proposed Development are expected to remain reasonably consistent in the future. In the longer term, there may be increases in wind farm related traffic associated with the ScotWind developments north and east of the Proposed Development. However, given the low data confidence associated with these developments it was not possible to make any quantitative assumptions. It has been assumed that future case traffic growth is likely to fluctuate depending on seasonality and cargo and industry trends. The Scotwind developments will be located offshore and therefore the extent to which grey seals from Isle of May SAC may be affected will depend on the location of the port/harbour that the vessels will be travelling to/from. It is an industry standard that vessels follow a Code of Conduct, which include advice not to approach marine mammals and it is anticipated that vessels at all relevant projects will follow these guidelines.
1382 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of underwater noise during vessel use and other activities during the operation and maintenance phase with respect to the Proposed Development acting in-combination with Tier 2 projects.
Tier 3
1383 There is potential for in-combination effects from underwater noise due to vessel use and other activities to grey seal from Isle of May SAC during the operation and maintenance of the Proposed Development with activities associated with the operation of Cambois connection.
1384 As presented in paragraph 1361, there were no details about the number of vessel round trips or type of vessels that will be used during operation and maintenance phase of Cambois connection (SSE Renewables, 2022e). Due to lack of detailed project information at this stage, it was not possible to undertake full, quantitative assessment for this impact.
1385 An overview of potential impacts for behavioural disturbance to grey seal from the Isle of May SAC from elevated underwater noise due to vessel use and other activities is described in paragraph 1360 et seq. for the construction phase and have not been reiterated here for the operation and maintenance phase.
1386 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of underwater noise during vessel use and other activities during the operation and maintenance phase with respect to the Proposed Development acting in-combination with Tier 3 projects.
Changes in fish and shellfish communities affecting prey availability
Tier 2
1387 There is potential for in-combination effects from changes in prey resources to grey seal from the Isle of May SAC during the operation and maintenance phase of the Proposed Development with activities associated with the following projects: Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, Seagreen 1A Export Cable, Eastern Link 1, Eastern Link 2, and Eyemouth disposal site.
1388 Operation and maintenance activities at respective projects considered in in-combination assessment may lead to temporary subtidal habitat loss/disturbance of up to 32,276,397 m2. Additionally, Offshore Wind Farms listed above will reach their decommissioning age during Proposed Development operation and maintenance phase. However, it is important to note that the maximum design scenario for habitat loss from the in-combination projects is precautionary, as operation and maintenance activities will occur intermittently throughout the lifetime of the Proposed Development and the temporal overlap with activities at other projects is unlikely. Only a small proportion of the maximum footprint of habitat loss/disturbance may be affected at any one time, areas are starting to recover immediately after cessation of maintenance activities. It is expected that grey seal could come back to forage within areas previously disturbed after cessation of works and therefore their distribution and connectivity with important habitats within and outside the site is unlikely to be impaired in long term.
1389 In-combination impacts could arise from EMFs due to the presence of subsea cabling during the operation and maintenance phases of the Proposed Development as well as Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project and Seagreen 1A Export Cable, Eastern Link 1 and Eastern Link 2. A total length of up to 6,112 km of subsea cabling was estimated for all projects. The effect of EMF was predicted to be of local spatial extent
1390 As outlined in paragraph 1023 et seq., while grey seal has a relatively selective diet of predominantly flatfish and sandeel, the species can forage widely, sometimes covering extensive distances. Given that the impacts of temporary and long-term will be localised when compared to wider habitat available and largely restricted to the boundaries of the respective projects, only a small area will be affected when compared to available foraging habitat for grey seals in the northern North Sea. Since the habitat is likely to return to the state that existed before the activity or event which caused change, the availability of suitable food supply for grey seals is not expected to be impaired hence the population trajectory is unlikely to be affected in the long-term. Considering the above, adverse effects on grey seal as a result of changes in prey availability due to EMF are unlikely.
1391 Artificial structures introduced into areas of predominantly soft sediments has the potential to alter community composition and biodiversity. There is a potential for in-combination effects arising from colonisation due to the presence of Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1, Seagreen 1A Project, and Seagreen 1A Export Cable Corridor, Eastern Link 1 and Eastern Link 2 with a maximum scenario of up to 15,014,156 m2 of hard structures from wind turbines, OSP/Offshore convertor station platforms, meteorological masts, of cable protection, and cable crossings. The in-combination effect was predicted to be of local spatial extent. There is some evidence that marine mammal populations are likely to benefit from introduction of hard substrates and associated fauna, as studies reported that grey seal were frequently recorded around offshore oil and gas structures (see paragraph 1022 for more details). Therefore, it is highly unlikely that placement of man-made structures on the seabed will adversely influence grey seal SAC population trajectory.
1392 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of changes in fish and shellfish communities affecting prey availability during operation and maintenance with respect to the Proposed Development acting in-combination with Tier 2 projects.
Tier 3
1393 There is potential for in-combination effects from changes in fish and shellfish communities affecting prey availability to grey seal from the Isle of May SAC during the operation and maintenance phase of the Proposed Development with activities associated with the operation of Cambois connection.
1394 In terms of temporary subtidal habitat loss/disturbance, there are no specific values for the operation and maintenance phase of Cambois connection which will occur during the operation and maintenance phase of the Proposed Development. However, Cambois connection has the potential to result in cumulative EMF effects from subsea electrical cabling within the Proposed Development. The Cambois connection is understood to have 680 km of cable. The effect of EMF was predicted to be of local spatial extent.
1395 The Cambois connection has the potential to create 306,000 m2 of new hard habitat associated with rock/mattress cable protection, which represents a change in seabed type, the effects of which are described in paragraph 1022 et seq. As the cable protection does not extend into the water column the opportunity for colonisation by some species is reduced, nevertheless there is a potential that placement of man-made structures on the seabed will benefit grey seal population.
1396 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Isle of May SAC as a result of changes in fish and shellfish communities affecting prey availability during operation and maintenance with respect to the Proposed Development acting in-combination with Tier 3 projects.
Site conclusion
1397 In conclusion, with reference to the conservation objectives set for the Annex II marine mammal features of the site and the information presented in section 13.3, 13.4, 13.5 and 13.6.2, it can be concluded beyond all reasonable scientific doubt that there will be no Adverse Effect on Integrity on the Isle of May SAC in respect of the grey seal qualifying interests, as a result of the Proposed Development.
1398 This finding is in relation to potential impacts associated with the Proposed Development during construction, decommissioning and operation and maintenance, acting alone and or in-combination.
13.6.3 Firth of Tay and Eden Estuary SAC
European site information
1399 The Firth of Tay and Eden Estuary SAC lies approximately 47 km from the Proposed Development array area and 45 km from the Proposed Development export cable corridor, covers an area of approximately 155 km2 and comprises two high quality estuarine areas, which are integral components of a large, geomorphologically complex area (JNCC, 2021a). The SAC supports a breeding colony of harbour seal. It has been documented that there has been a slow decline of harbour seal numbers over the period since 1990 (Hanson et al., 2015). From 2002 to 2017 the harbour seal count for the Firth of Tay and Eden Estuary SAC decreased rapidly at approximately 18.6% p.a. (see volume 3, appendix 10.2, annex B of the Offshore EIA Report). Subsequently, the count in 2019 for this SAC was 41 individuals, which represents a 95% decrease from the mean counts recorded between 1990 and 2002 (SCOS, 2020). Sporadic counts in the Firth of Forth indicate, however, that the decline is localised within the SAC and may not represent the trends in the overall MU population.
1400 The harbour seal feature of the site was last assessed as being in ‘unfavourable declining’ condition due to recreation/disturbance in August 2013[18].
1401 Further information on this European site is presented in appendix A.