Operation and maintenance
Injury and disturbance from elevated underwater noise during site investigation surveys
1703 As discussed in paragraph 945 et seq., the maximum range at which there is a risk of PTS to bottlenose dolphin as a result of site investigation surveys is 65 m. With designed in measures ( Table 13.11 Open ▸ ) implemented for the geophysical surveys, the risk of PTS occurring to bottlenose dolphin will be low. With regard to behavioural disturbance, a maximum potential disturbance range across all survey types is approximately 7.5 km during vibro-coring. Due to the coastal distribution of bottlenose dolphins from the Moray Firth SAC, if surveys are taking place within the Proposed Development array area, there will be no overlap of injury and disturbance ranges with their distributional range and it is highly unlikely that individuals from this SAC will be present in offshore waters. If site investigation surveys are taking place along Proposed Development export cable corridor and nearby at the landfall at Skateraw on the East Lothian coast, there is a potential for overlap of injury ranges with coastal areas. However, the landfall is located at the southern limit of the main distributional range of bottlenose dolphin from the Moray Firth SAC and based on the ECOMMAS study, the C‐PODs deployed at the closest station at St. Abbs had very low (<5%) broadband occupancy rates for all survey years (2013 to 2015). Given that the surveys are considered to be short-term (i.e. they will take place over a period of up to three months), number of animals potentially disturbed would represent a negligible proportion of the population.
1704 The maximum design scenario for routine geophysical surveys is estimated as a survey every six months for the first two years and annually thereafter. This equates to 37 surveys over the 35-year life cycle of the Proposed Development ( Table 13.10 Open ▸ ). The site-investigation surveys will be taking place outside the Moray Firth SAC and there is no potential for overlap of injury ranges or noise disturbance contours with the limits of the site. Areas within the SAC are important for breeding and calving but given that there will be no overlap of the activity with areas used by dependant mothers and calves, site investigation surveys are unlikely to affect bottlenose dolphins within the SAC at a level that would affect their behaviour and cause change in reproduction and survival rates.
1705 Site investigation surveys are expected to be very short in duration with animals returning to baseline levels soon after surveys have ceased. Given that the potential disturbance will be localised and short term, it is not considered to cause levels of disturbance that would raise concern. Therefore it is highly unlikely that site investigation surveys will influence bottlenose dolphin population trajectory in the long-term. As the site investigation surveys will take place largely outside the CES MU, it is not anticipated that there will be any introduction of barriers to wider movement or impact to connectivity between different important habitats for bottlenose dolphin from the Moray Firth SAC as a result of site investigation surveys.
1706 Significant adverse effects on the qualifying Annex II marine mammal feature, bottlenose dolphin of the Moray Firth SAC, are not predicted to occur as a result of underwater noise during site investigation surveys during the operation and maintenance phase (i.e. in relation to maintaining the population, distribution of species within the site, connectivity and disturbance to species).
Conclusion
1707 . The assessment has concluded that site investigation surveys will not take place within the Moray Firth SAC. Given that disturbance range do not extend to the Moray Firth SAC and only small number of animals may experience behavioural disturbance within the CES MU, behavioural disturbance will not be significant. There will be no behavioural disturbance with areas used by dependant mothers and calves, therefore it is highly unlikely that the reproductive and recruitment capability of the species will be affected. The population of bottlenose dolphin will remain a viable component of the site. Site investigation surveys will not affect the condition of supporting habitats and processes. As such, the conservation objectives for Annex II species, harbour porpoise, will not be undermined.
1708 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity of the Moray Firth SAC from injury and disturbance due to underwater noise during site investigation surveys with respect to the operation of the Proposed Development acting alone.
Injury and disturbance from elevated underwater noise during vessel use and other activities
1709 As described in paragraphs 989 et seq., vessel use during the operation and maintenance phase of the Proposed Development is considered to represent a relatively small increase in the context of baseline traffic. Furthermore, the size and noise outputs from vessels will be similar to those used in the construction phase. The number of vessel round trips and their frequency will, however, be much lower compared to the construction phase.
1710 All vessel movements will be taking place outside the Moray Firth SAC and there is no potential for overlap of injury or disturbance ranges with the limits of the site. Areas within the SAC are important for breeding and calving and given that there will be no overlap of the activity with areas used by dependant mothers and calves, vessel movements are unlikely to affect bottlenose dolphins at a level that would cause change in reproduction and survival rates. Therefore, vessel use and other activities are highly unlikely to affect bottlenose dolphin population in long-term.
1711 As described in paragraph 800, bottlenose dolphin from Moray Firth SAC are most likely to be encountered within 2 km from the shore. As most vessel movements during the operation and maintenance phase will be confined within the Proposed Development array area, there is a limited potential for overlap of maximum injury or behavioural disturbance ranges with coastal areas.
1712 However, small number of vessel movements will be also taking place along the Proposed Development export cable corridor and nearby at the landfall at Skateraw on the East Lothian coast. The landfall is located at the southern limit of the main bottlenose dolphin distributional range and based on ECOMMAS study, the C‐PODs deployed at closest station at St. Abbs had very low (<5%) broadband occupancy rates for all survey years (2013 to 2015). Therefore, if individuals are affected by disturbance as a result by vessel movements and other activities in the vicinity of the Proposed Development export cable corridor and landfall, these numbers would represent a negligible proportion of the population from Moray Firth SAC.
1713 Vessels will be moving to and from ports and harbours; this traffic will intersect with the CES MU and areas of high bottlenose dolphin abundance. The NSPVMP will be produced and will include agreed routes and potential speed restrictions in order to reduce disturbance. The Moray Firth is an area of relatively high vessel traffic due to the presence of the port of Cromarty Firth which has been supporting offshore energy industry for decades. The Moray Firth SAC is located within this busy area and yet population of bottlenose dolphin within the SAC is increasing. Therefore, given the existing levels of vessel activity within the Moray Firth and along the east coast of Scotland, it is expected that bottlenose dolphin could tolerate the effects of vessel activity during the operation and maintenance phase. Lusseau et al. (2011) undertook a modelling study which predicted that increased vessel movements associated with offshore wind development in the Moray Firth did not have an adverse effect on the local population of bottlenose dolphin, although it did note that foraging may be disrupted by disturbance from vessels. Vessel movements intersecting the bottlenose dolphin main distributional range will be intermittent and localised and animals could be potentially disturbed from only a small area when compared to available foraging habitat. Therefore, it is anticipated that the availability of suitable foraging grounds for bottlenose dolphin will not be impaired.
1714 Given that increase in vessel movements will take place largely outside the CES MU, it is anticipated that there will be no introduction of barriers to wider movement or impact to connectivity between different important habitats for bottlenose dolphin from the Moray Firth SAC.
1715 Effects on bottlenose dolphin at this SAC are considered to be the same or less than the effects described for vessel use and other activities during the construction and decommissioning phases, previously described in paragraph 1684 et seq. It should be noted that operation and maintenance activities will occur over the full lifetime of the project (estimated to be 35 years) and therefore only a small proportion of vessel movements and other activities will occur at any one time.
1716 Significant adverse effects on the qualifying Annex II marine mammal feature, bottlenose dolphin of the Moray Firth SAC, are not predicted to occur as a result of underwater noise during vessel use and other activities during the operation and maintenance phase (i.e. in relation to maintaining the population, distribution of species within the site, connectivity and disturbance to species).
Conclusion
1717 The assessment has concluded that vessel use and other activities will not take place within the Moray Firth SAC. Given that the behavioural disturbance range do not extend to the Moray Firth SAC and only small number of animals may experience it within the CES MU, disturbance will not be significant. There will be no disturbance with areas used by dependant mothers and calves, therefore it is highly unlikely that the reproductive and recruitment capability of the species will be affected. The population of bottlenose dolphin will remain a viable component of the site. Vessel use and other activities will not affect the condition of supporting habitats and processes. As such, the conservation objectives for Annex II species, bottlenose dolphin, will not be undermined.
1718 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth SAC from injury and disturbance due to underwater noise during vessel use and other activities with respect to the operation of the Proposed Development acting alone.
Changes in fish and shellfish communities affecting prey availability
1719 As outlined in paragraph 1051 et seq., there is potential for changes to prey availability for bottlenose dolphin 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.
1721 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. The assessment presented in volume 2, chapter 9 of the Offshore EIA Report considered that any suspended sediments and associated deposition will be of the same magnitude, or lower as for construction.). Therefore, the availability of suitable food supply for bottlenose dolphin is not expected to be impaired as a result of increase in SSC and associated deposition.
1722 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 bottlenose dolphin as a result of changes in prey availability due to EMF are unlikely.
1723 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 are increased around offshore wind farm structures. However, due to coastal distribution, bottlenose dolphins from Moray Firth SAC are unlikely to benefit from the presence of artificial structures in offshore waters.
1724 Significant adverse effects on the qualifying Annex II marine mammal feature, bottlenose dolphin of the Moray Firth 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
1725 The assessment has concluded that the impacts of construction and decommissioning will be highly localised and largely restricted to the boundaries of the Proposed Development. Given that important feeding areas within the CES MU will not be affected, the supporting habitats relevant to bottlenose dolphin and the availability of prey for bottlenose dolphin will be maintained.
1726 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity of the Moray Firth 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
1727 An assessment of in-combination effects upon the qualifying Annex II marine mammal species of the Moray Firth SAC arising from each identified impact is provided below.
1728 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 cumulative impacts for injury from elevated underwater noise during pilling and vessel use/other activities and the cumulative 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
1730 All projects screened in for the in-combination assessment for bottlenose dolphin are located within, or close to, the main distributional range of the population, restricted to the Moray Firth and coastal waters of the eastern Scotland ( Figure 13.8 Open ▸ ). Population level modelling predicted that displacement from pile driving at Inch Cape is unlikely to affect the size or growth of the bottlenose dolphin population off the east coast of Scotland. Results of population modelling for Moray West indicated that none of the bottlenose impact scenarios discussed in the EIA resulted in a significant long term population effects (Moray West, 2018).
Figure 13.8: Unweighted Single Pulse SEL Contours Due to Concurrent Impact Piling at Maximum Hammer Energy (4,000 kJ) Overlaid with Proposed Development and Projects Located Within a Distributional Range of Bottlenose Dolphin Population
1731 The assessment presented in the Inch Cape EIA (Inch Cape Offshore Limited, 2018), original Seagreen EIA (Seagreen Wind Energy Ltd, 2012) and Moray West EIA (Moray West, 2018) estimated that eight, four and 15 bottlenose dolphins could experience disturbance during piling at respective projects. A spatial maximum adverse scenario would occur where piling activities occur concurrently at the respective projects considered in the in-combination assessment. This is however highly unlikely, as the construction of Moray West Offshore Wind Farm will be completed two years before commencement of piling phase at Proposed Development. Although there is an overlap with the piling operations at Seagreen 1A Project and Inch Cape, construction of these wind farms will be completed prior to commencement of piling at the Proposed Development. 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 all projects listed in paragraph 1729 and respective numbers of animals potentially impacted against the MU population (see volume 3, appendix 10.4 for methods applied in the model). Results of the cumulative iPCoD modelling for bottlenose dolphin showed that the difference in population trajectory between the impacted and unimpacted population (up to 3.5%) falls within the natural variance of the wider population. Therefore, it was considered that there is no potential for the long-term effects on this species within the wider MU population as a result of cumulative piling at proposed Development and respective projects (see volume 3, appendix 10.4 for more details).
1732 The noise contours resulting from piling at respective projects have the potential to overlap with the main distributional range of Moray Firth SAC population (CES MU). Although the construction of projects considered in in-combination assessment will be completed prior to commencement of piling at the Proposed Development, 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. Moray West is located at a closest distance to the Moray Firth SAC. As mentioned above, the gap between construction phase of Moray Firth and piling at Proposed Development is two years. It is anticipated that if bottlenose dolphins experienced any disturbance as a result of piling at Moray West, individuals would return to previous activities once the impact had ceased and therefore no in-combination effects with Proposed Development are predicted.
1733 For the Proposed Development alone, received noise levels within the 2 m to 20 m depth contour are predicted to reach maximum SELss levels of 130 dB and could lead to mild disruptions of normal behaviours but prolonged or sustained behavioural effects, including displacement, are unlikely to occur. Piling activities will take place intermittently over several years and there is a potential for bottlenose dolphins close to key foraging area in the Firth of Tay to experience mild disturbance. Results of studies on bottlenose dolphins in Moray Firth suggest that impulsive noise generated during piling at the offshore wind farms does not cause any displacement of bottlenose dolphins from their population range (Fernadex-Betelu et al., 2021). Although foraging activities may be temporarily disrupted if piling will occur closer to the coast, bottlenose dolphins will still have access to sufficient food resources within the wider CES MU. Therefore, behavioural disturbance is unlikely to alter the distribution of bottlenose dolphin within the SAC such that recovery cannot be expected, or effects can be considered long term.
1734 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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
1736 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 bottlenose dolphin 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 945 et seq. is based on the maximum disturbance range estimated as 7,459 m for vibro-coring. Given that the vibro-core sampling locations are currently unknown and coastal distribution of bottlenose dolphin is spatially limited, any quantitative assessment of the disturbance to coastal populations would be an overestimation.
1737 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 nearby at the landfall at Skateraw on the East Lothian coast ( Figure 13.3 Open ▸ ). However, the landfall is located at the southern limit of the main bottlenose dolphin distributional range and based on ECOMMAS study, the C‐PODs deployed at closest station at St. Abbs had very low (<5%) broadband occupancy rates for all survey years (2013 to 2015). Given that the surveys are considered to be short-term (i.e. they will take place over a period of up to three months), number of animals potentially disturbed would represent a negligible proportion of the population.
1738 Additionally, as outlined in paragraph 1720 et seq, within the CES MU, the Moray Firth SAC and the Tay estuary are known to be important foraging ground for bottlenose dolphins (Arso Civil et al., 2021). Given that neither of these important areas will be affected by disturbance as a result of site investigation surveys at either of the projects, bottlenose dolphin distribution and connectivity with important foraging habitats within and outside the site is unlikely to be impaired.
1739 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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
1740 There is potential for in-combination effects from injury and/or disturbance from underwater noise during UXO clearance to bottlenose dolphin from the Moray Firth SAC during the construction phase of the Proposed Development with activities associated with the following projects Inch Cape Offshore Wind Farm and Moray West Offshore Wind Farm.
1741 Projects screened in for this cumulative 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.
1742 For the Proposed Development alone, the maximum range across which bottlenose dolphin have the potential to experience PTS due to high order detonation of 300 kg charge was assessed as approximately 615 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 not 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, there will be no residual risk of injury (see paragraph 961 et seq.) and therefore, it is highly unlikely that the reproductive and recruitment capability of the species will be affected.
1743 In terms of TTS, for the Proposed Development alone, the range across which bottlenose dolphin have the potential to experience TTS due to high order detonation of a 300 kg charge was as approximately 1,137 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 cumulative 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 CEA 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 cumulative effects with respect to TTS is considered to be very limited. Given that effect of TTS is short in duration, connectivity with important habitats within and outside the site is also unlikely to be impaired.
1744 Quick et al. (2014) reported that males appear to spend more time outside the Moray Firth SAC than females, therefore males are more exposed to pressures outside the SAC. Given that there is a small risk that any animals potentially injured will be female, there is low risk to population decline as it is highly unlikely that reproductive female will be removed from the population. The UXO clearance activities at respective projects will be taking place outside the Moray Firth SAC and the potential for overlap of injury ranges with the limits of the site is highly unlikely. Areas within the SAC are important for breeding and calving and given that no overlap of the UXO clearance activity with areas used by dependant mothers and calves is anticipated, UXO clearance activities are unlikely to affect bottlenose dolphins at a level that would cause change in reproduction and survival rates. Therefore, UXO clearance activities are highly unlikely to affect bottlenose dolphin population in long-term.
1745 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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
1746 There is potential for in-combination effects from injury and/or disturbance from underwater noise due to vessel use and other activities to bottlenose dolphin from the Moray Firth 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, Neart na Gaoithe and Blyth Demo 2.
1747 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 995 et seq.). In terms of behavioural disturbance, the noise modelling for the Proposed Development alone predicted a maximum range of approximately 4 km for construction activities such as cable laying (described in detail in volume 3, appendix 10.1). Although there is a potential for disturbance effects to occur cumulatively, these will be localised to the vessel routes to and from ports and harbours, intersecting the CES MU. The highest number of vessels movements was predicted during the construction phase of each offshore wind farm. There would potentially be a relatively small temporal overlap of the construction phases, with only one year of overlap with Inch Cape as well as Seagreen 1A Project and the Proposed Development. There will be no overlap with construction phase at Moray West. Therefore, the potential cumulative effect during construction phases of the respective projects and the proposed Development will be short-term (no more than one year).
1748 It is an industry standard that vessels follow a Code of Conduct, which includes advice not to approach marine mammals and it is anticipated that vessels at all relevant projects will follow these guidelines. Given the existing levels of vessel activity within the Moray Firth and along the east coast of Scotland, it is expected that bottlenose dolphin could tolerate the effects of vessel presence. Although foraging activities may be temporarily disrupted when vessel movements occur closer to the coast, it is expected that bottlenose dolphins will still have access to sufficient food resources within the wider CES MU. Therefore, behavioural disturbance is unlikely to alter the distribution of bottlenose dolphin within the SAC such that recovery cannot be expected, or effects can be considered long term.
1749 Most vessel movements will be confined within the array areas of respective projects as well as routes to and from ports, therefore there is limited potential for overlap of behavioural disturbance ranges with coastal areas. Although connectivity between the SAC and vessel traffic associated with Moray West can’t be discounted, most vessel movements from respective projects considered in in-combination assessment will be taking place outside the Moray Firth SAC. The predicted levels of increase in vessel activity resulting from the Moray West project alone will not represent a significant increase above baseline levels of ship activity in the Moray Firth and is not expected to increase the potential for disturbance above that already experienced in the region (Moray West, 2018). As such, vessel movements are unlikely to affect bottlenose dolphins at a level that would cause change in reproduction and survival rates.
1750 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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.
Changes in fish and shellfish communities affecting prey availability
Tier 2
1751 There is potential for in-combination effects from changes in the prey resources available for bottlenose dolphin from the Moray Firth SAC as a result of changes to the fish and shellfish community during the construction and decommissioning phases of the Proposed Development with activities associated with the following projects: Inch Cape Offshore Wind Farm, Neart na Gaoithe Offshore Wind Farm, Seagreen 1 Offshore Wind Farm, Seagreen 1A Project, Seagreen Eastern Link 1, Seagreen 1A Export Cable Corridor, Eastern Link 2 and Eyemouth disposal site.
1752 The construction phases and/or operation and maintenance phases of projects screened into in-combination assessment 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). As outlined in paragraph 1720 et seq, Moray Firth SAC and the Tay estuary are known to be important foraging ground for bottlenose dolphins within the CES MU (Arso Civil et al., 2021). Given that neither of these important areas will be affected by temporary habitat loss/disturbance or long term habitat loss, bottlenose dolphin distribution and connectivity with important foraging habitats within and outside the site is unlikely to be impaired. It is therefore highly unlikely that construction works resulting in habitat loss/disturbance will influence bottlenose dolphin population trajectory in the long-term.
1753 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 bottlenose dolphin. 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 the localised extent of this effect, the availability of suitable food supply for bottlenose dolphin within the wider area is not expected to be impaired.
1754 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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
1755 There is potential for in-combination effects from injury and/or disturbance from underwater noise due to site investigation surveys to bottlenose dolphin during the operation and maintenance phase of the Proposed Development with the operation and maintenance Eastern Link 1 and Eastern Link 2.
1756 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 1736, 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.
1757 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 1735 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 bottlenose dolphin in the short-term only where it overlaps with their main distributional range. Surveys are anticipated to be short-term in nature (weeks to a few months) and occur intermittently over the operation and maintenance phase.
1758 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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
1760 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). During the operation and maintenance phase of the Proposed Development, the wind farms listed in paragraph 1759 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.
1761 Most vessel movements will be confined within the array areas of respective projects as well as routes to and from ports, therefore there is limited potential for overlap of behavioural disturbance ranges with coastal areas. Although connectivity between the SAC and vessel traffic associated with Moray West can’t be discounted, most vessel movements from respective projects considered in in-combination assessment will be taking place outside the Moray Firth SAC. The predicted levels of increase in vessel activity resulting from the Moray West project alone will not represent a significant increase above baseline levels of ship activity in the Moray Firth and is not expected to increase the potential for disturbance above that already experienced in the region (Moray West, 2018). As such, vessel movements are unlikely to affect bottlenose dolphins at a level that would cause change in reproduction and survival rates. Therefore, vessel use and other activities are highly unlikely to affect bottlenose dolphin population in long-term.
1762 Additionally, given the existing levels of vessel activity within the Moray Firth and along the east coast of Scotland and the fact that at the time of operation and maintenance of Proposed Development, construction activities within the Firth of Forth will be happening for over 10 years, it is expected that bottlenose dolphin will be able to tolerate the effects of vessel presence. Lusseau et al. (2011) undertook a modelling study which predicted that increased vessel movements associated with offshore wind development in the Moray Firth did not have an adverse effect on the local population of bottlenose dolphin, although it did note that foraging may be disrupted by disturbance from vessels. Vessel movements across the bottlenose dolphin main distributional range will be intermittent and localised and animals could be potentially disturbed from only a small area when compared to available foraging habitat. Therefore, it is anticipated that the availability of suitable foraging grounds for bottlenose dolphin will not be impaired.
1763 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 bottlenose dolphins 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 and Vessel Management Plan, which include advice not to approach marine mammals and it is anticipated that vessels at all relevant projects will follow these guidelines.
1764 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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.
Changes in fish and shellfish communities affecting prey availability
Tier 2
1765 There is potential for in-combination effects from changes in prey resources to bottlenose dolphin from the Moray Firth SAC during the operation and maintenance phase of the Proposed Development with maintenance 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.
1766 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 cumulative 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. As described in paragraph 1011, only a small proportion of the maximum footprint of habitat loss/disturbance may be affected at any one time, areas are starting to recover
1767 immediately after cessation of maintenance activities. The Moray Firth SAC and the Tay estuary are known to be important foraging ground for bottlenose dolphins from Moray Firth SAC (Arso Civil et al., 2021). Given that neither of these important areas will be affected by temporary habitat loss/disturbance or long term habitat loss, bottlenose dolphin distribution and connectivity with important foraging habitats within and outside the site is unlikely to be impaired. It is therefore highly unlikely that operation and maintenance works resulting in habitat loss/disturbance will influence bottlenose dolphin population trajectory in the long-term. 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, 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. Considering the above, adverse effects on bottlenose dolphin as a result of changes in prey availability due to EMF are unlikely.
1768 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, 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 cumulative effect was predicted to be of local spatial extent. It is 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 are increased around offshore wind farm structures. However, due to coastal distribution, bottlenose dolphins from Moray Firth SAC are unlikely to benefit from presence of artificial structures in offshore waters.
1769 Therefore, it can be concluded that there is no risk of an Adverse Effect on Integrity on the Moray Firth 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.
Site conclusion
1770 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 13.6.5, it can be concluded beyond all reasonable scientific doubt that there will be no Adverse Effect on Integrity on the Moray Firth SAC in respect of the bottlenose dolphin qualifying interests.
1771 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.