6.2.7. Potential Impacts After the Implementation of Designed in MeasuresPotential Impacts After the Implementation of Designed in Measures
- Table 6.9 Open ▸ outlines the impacts which have been scoped into the Array assessment alongside a description of any additional and/or supporting analyses (e.g. modelling) that will be required to enable a full assessment of the impacts.
- Table 6.10 Open ▸ describes the potential impacts to fish and shellfish ecology that have been scoped out of the assessment presently.
Table 6.9: Impacts Proposed to be Scoped In to the Array Assessment for Fish and Shellfish Ecology. Project Phase Refers to Construction (C), Operation and Maintenance (O) and Decommissioning (D) Phase of the Array
Table 6.10: Impacts Proposed to be Scoped Out of the Array Assessment for Fish and Shellfish Ecology
6.2.8. Proposed Approach to the Environmental Impact AssessmentProposed Approach to the Environmental Impact Assessment
- The methodology set out in section 4 will be followed when preparing the Fish and Shellfish Ecology chapter of the Array EIA Report. The following guidance documents will also be considered with regard to fish and shellfish ecology:
- Guidelines for Ecological Impact Assessment (EcIA) in the UK and Ireland. Terrestrial, Freshwater, Coastal and Marine (CIEEM, 2019);
- Consenting, EIA, and Habitat Regulations Assessment (HRA) Guidance for Marine Renewable Energy Developments in Scotland (European Marine Energy Centre (EMEC) and Xodus, 2010); and
- Guidance on Environmental Considerations for Offshore Wind Farm Development (OSPAR, 2008).
- Diadromous fish will be included in the fish and shellfish ecology impact assessment. A separate section covering sensitivity of and implications of the impact on diadromous fish in each impact assessment will be included. Discussion with stakeholders throughout the consultation process will be undertaken to finalise the approach and focus of these impact assessments.
- The importance of key forage fish species, such as herring, sandeels and sprat, as prey for other fauna (such as marine mammals and birds) will be assessed in section 6.3 and section 6.4. These will be informed by clear outputs provided in the Fish and Shellfish Ecology chapter of the Array EIA Report.
- Herring and sandeel habitat suitability assessments will be informed by data collected as part of the benthic subtidal ecology survey (Appendix 7). This will be undertaken in line with good industry practice guidelines and informed by discussion with stakeholders during the consultation process.
- A detailed baseline characterisation for the Array will be presented in a Fish and Shellfish Ecology Technical Report. This will be informed using site-specific survey data and the most recent desktop data (see Appendix 8 for further details). This report will inform the Fish and Shellfish Ecology chapter of the Array EIA Report.
6.2.9. Potential Cumulative EffectsPotential Cumulative Effects
- The key cumulative effect on fish and shellfish ecology is likely to arise from increased subsea noise during piling which has the potential to have a zone of influence (ZoI) extending beyond the site boundary. There is the potential for cumulative effects in-combination with other offshore wind farm developments in the region (including the Proposed offshore export cable corridor(s) and Proposed onshore export cable corridor(s)) where piling is conducted concurrently or sequentially. Noise propagation modelling will be used to determine a zone of influence associated with percussive piling and UXO clearance. The noise contours associated with these impacts will be used to screen for potential cumulative effects.
- Predicted effects from other impacts associated with the Array during the construction, operation and maintenance, and decommissioning phases, are considered to be localised within or immediately adjacent to the footprint of the site boundary with no potential for cumulative effects. Section 4.3.7 outlines the approach that the cumulative effects assessment will be based upon.
6.2.10. Potential Transboundary ImpactsPotential Transboundary Impacts
- Appendix 3 presents the transboundary impacts screening which has been carried out for the Array. This screening exercise identified that there is no potential for transboundary impacts upon fish and shellfish ecology due to construction, operation and maintenance, and decommissioning phases of the Array.
6.2.11. Scoping Questions to ConsulteesScoping Questions to Consultees
- Do you agree with the study area defined for fish and shellfish ecology?
- Do you agree that the existing data available to describe the fish and shellfish ecology baseline remains sufficient to describe the baseline environment in relation to the Array? Are there any further desktop datasets which you would recommend are included?
- Do you agree that the designed in measures described provides a suitable means for managing and mitigating the potential effects of the Array on the fish and shellfish ecology receptors?
- Do you agree that all potential impacts ( Table 6.9 Open ▸ ) have been identified for fish and shellfish ecology?
- Do you agree that the impacts described in Table 6.10 Open ▸ should be scoped out of the Array EIA for fish and shellfish ecology?
6.2.12. Next StepsNext Steps
- The topic specific next step is to agree upon the assessment approach for fish and shellfish ecology and the potential impacts that will be assessed during the EIA process. This includes presenting the sensitivities of receptors that will be used in the assessment, and appropriate mitigation and monitoring to stakeholders. These impacts will be quantified using MDSs.
- In the event that any impacts cannot be quantitively assessed, they will be discussed with key stakeholders as part of the consultation process. The process for post-Scoping consultation is presented in the dSEP in Appendix 1.
- Potential monitoring (either site-specific or strategic) will be detailed in the Fish and Shellfish Ecology chapter of the Array EIA Report. This further monitoring will be discussed with stakeholders through the consultation process.
6.3. Marine MammalsMarine Mammals
6.3.1. IntroductionIntroduction
- This section of this Scoping Report presents the relevant marine mammal data sources and baseline description within the Array and considers the scope of assessment on marine mammals from the construction, operation and maintenance, and decommissioning of the Array.
6.3.2. Study AreaStudy Area
- Marine mammals are highly mobile, wide-ranging species, with varied behaviour and ecology between species. To account for this and provide wider geographic context, the marine mammal study area proposed for the purpose of baseline characterisation and subsequent Array EIA Report has been defined at two spatial scales:
- Array marine mammal study area: this includes the area covered by the site-specific aerial surveys (March 2021 to February 2023). The preliminary results of these surveys provided an indication of the marine mammal species currently present within potential impact footprints associated with the Array (i.e. the potential Zones of Influence (ZoI)). The Array marine mammal study area encompasses the site boundary plus an 8 km buffer, which is based on the buffer implemented in the site-specific aerial surveys. The Array marine mammal study area is shown in Figure 6.4 Open ▸ ; and
- Regional marine mammal study area: this area encompasses a larger range due to the highly mobile and wide-ranging nature of marine mammal species and is illustrated in Figure 6.4 Open ▸ and Figure 6.5 Open ▸ . Management Units (MUs) were used to inform the regional marine mammal study area at appropriate scales for each species, with cetacean MUs defined by the Inter Agency Marine Mammal Working Group (IAMMWG, 2015) and seal MUs provided by the Special Committee on Seals (SCOS, 2021). For species in which MUs extend over a very large scale (e.g. the Celtic and Greater North Sea MU for minke whale Balaenoptera acutorostrata and white-beaked dolphin Lagenorhynchus albirostris, and North Sea MU for harbour porpoise Phocoena phocoena) the appropriate Small Cetaceans in European Atlantic waters and the North Sea survey (SCANS)-III block which overlaps with the Array (block R) will be utilised. The different MUs for the target species are presented in Figure 6.5 Open ▸ .
Figure 6.4: Marine Mammal Study Areas
Figure 6.5: Management Units for Relevant Marine Mammal Species in the Vicinity of the Array
6.3.3. Baseline EnvironmentBaseline Environment
- The marine mammal baseline environment of the Array is summarised briefly in this section, with a detailed description provided in Appendix 8. The baseline environment was characterised through an extensive desktop review of key datasets, the preliminary results from the site-specific aerial surveys undertaken (data available between March 2021 to September 2022 at the time of writing) and the results from site-specific surveys for nearby offshore wind farms (such as Seagreen 1 (formerly known as Seagreen Alpha and Bravo) and Berwick Bank Offshore Wind Farms). Seagreen 1 and Berwick Bank Offshore Wind Farms are 50.72 km and 56.77 km away from the site boundary, respectively.
- Four marine mammal species were identified as being likely to occur within the Array marine mammal study area and/or the regional marine mammal study area either seasonally or year-round, dependant on species. These species are:
- harbour porpoise;
- minke whale;
- white-beaked dolphin; and
- grey seal Halichoerus grypus.
- Additionally, there were four common dolphins Delphinus delphis and three harbour seal Phoca vitulina recorded in total from two sightings each. These were classed as rare or occasional visitors to the area and will not be carried forward in the assessment (refer to Appendix 8 for further details).
Harbour porpoise
- The Array marine mammal study area is located within the North Sea MU for harbour porpoise (IAMMWG, 2022), which has an estimated abundance of 346,601 individuals (CV: 0.09, 95% CI: 289,498 to 419,967) based on estimates from the SCANS-III survey (Hammond et al., 2017, 2021).
- The SCANS-III density estimate was 0.599 individuals per km2 (CV: 0.287) for survey Block R (Hammond et al., 2017, 2021). The predicted density surface of harbour porpoise in the Array marine mammal study area is between 0.5 to 1.2 animals per km2 (Appendix 3 by Lacey and Hammond in Hague et al., 2020).
- Sightings data between 1980 and 2018, collated by Waggitt et al. (2020), report year-round abundance of harbour porpoise, with increased density in the summer months. This is consistent with the results of the site-specific aerial surveys conducted for the nearby Berwick Bank Offshore Wind Farm, which reported higher densities during spring and summer than in autumn and winter (SSER, 2022). Additionally, harbour porpoise were the most abundant marine mammal recorded during the site-specific surveys for the Array, with a total of 825 individuals sighted thus far between March 2021 to September 2022. They were the only species to be observed in all months, with the highest number of individuals observed in July 2021 (n=187).
- Given their recorded abundance in the literature and recent site-specific surveys for the Array and nearby offshore wind farms, harbour porpoises are considered likely to occur within the Array marine mammal study area and regional marine mammal study area year-round.
Minke whale
- All minke whales in UK waters are part of the Celtic and Greater North Seas MU (IAMMWG, 2022). This MU has an estimated abundance of 10,288 individuals in the UK portion (CV: 0.26, 85% CI: 6,210 to 17,042) and 20,118 individuals in the entire MU (CV: 0.18, 95% CI: 14,061 to 28,786) based on estimates from the SCANS-III survey (Hammond et al., 2017, 2021) and ObSERVE survey (Rogan et al., 2018).
- The SCANS-III density estimate was 0.0387 individuals per km2 (CV: 0.614) for survey Block R (Hammond et al., 2017, 2021). The predicted density surface of minke whale in the Array marine mammal study area is between 0.03 to 0.05 animals per km2 (Appendix 3 by Lacey and Hammond in Hague et al., 2020).
- Minke whales are considered to be seasonal visitors to the northern North Sea, as they are mainly present in Scottish waters in the summer (Hague, et al., 2020, Waggitt et al., 2020). This is consistent with the preliminary results of the site-specific surveys for the Array which recorded minke whales in the summer only, with sixteen individuals recorded across June and July in 2021 and 2022. Similarly, they were only observed in the summer months in site-specific aerial surveys for Berwick Bank Offshore Wind Farm and Firth of Forth Round 3 Zone surveys (Sparling, 2012, SSER, 2022). Therefore, minke whales are considered likely to occur regularly in the summer months within the Array marine mammal study area and the regional marine mammal study area.
White-beaked dolphin
- All white-beaked dolphins in UK waters are part of the Celtic and Greater North Seas MU (IAMMWG, 2022). This MU has an estimated abundance of 34,025 individuals in the UK portion (CV: 0.28, 85% CI: 20,026 to 57,807) and 43,951 individuals in the entire MU (CV: 0.22, 95% CI: 28,439 to 67,924) based on estimates from the SCANS-III survey (Hammond et al., 2017, 2021) and ObSERVE survey (Rogan et al., 2018).
- The SCANS-III density estimate was 0.243 individuals per km2 (CV: 0.484) for Block R (Hammond et al., 2017, 2021). The predicted density surface of white-beaked dolphin in the Array marine mammal study area is between 0.05 to 0.2 animals per km2 (Appendix 3 by Lacey and Hammond in Hague et al., 2020).
- Waggitt et al. (2020) report year-round abundance of white-beaked dolphins in the Array marine mammal study area and regional marine mammal study area, with an increase in abundance in the summer months. This is consistent with the preliminary results of the site-specific surveys as individuals were observed between March to October, with highest numbers recorded in June and July (n=18 and 19, respectively). White-beaked dolphins were the second most abundant marine mammal observed during the site-specific surveys thus far, with a total of 72 individuals sighted across ten surveys. Given the literature and observations during recent site-specific surveys for the Array and other nearby offshore wind farms, white-beaked dolphins are considered likely to occur regularly (mostly likely in the summer months) within the Array marine mammal study area and regional marine mammal study area.
Grey seal
- The Array marine mammal study area is situated within the East Scotland MU, with potential overlap with the Northeast England MU and Moray Firth MU (SCOS, 2021). This overlap with further away MUs is due to extensive offshore foraging trips undertaken by grey seals (McConnell et al., 2001; Jones et al., 2015; SCOS, 2021).
- The most recent population estimate of grey seals in Scotland at the start of the breeding season (before pups are born) was 120,800 individuals in 2020, and 157,300 in the wider UK (SCOS, 2021). The most recent estimated pup production from 2019 was 54,050 pups in Scotland and 67,850 in the wider UK (SCOS, 2021). The overall pup production in the wider UK increased by <1.5% per year between 2016 and 2019, with increases mainly limited to North Sea colonies along the east coast of Scotland and England (SCOS, 2021).
- August haul out counts for the East Scotland MU have increased from 2,328 individuals during the 1996-1997 survey to 3,683 in the 2016-2019 survey (Morris et al., 2021), accounting for 14% of grey seals hauled out in Scotland and 9% of grey seals hauled out in the UK. August haul out counts for the Moray Firth MU population increased from 551 individuals in the 1996-1997 survey to 1,917 in the 2011-2015 survey, with a decrease to 1,657 in the 2016-2019 survey (Morris et al., 2021). There are infrequent counts for the Northeast England MU, with grey seals primarily present in the Northumberland and The Tees areas. These counts show a significant increase from 613 individuals in the 1996-1997 period to 6,565 in the 2016-2019 period (SMRU, 2022b).
- Grey seals were observed year-round during the site-specific surveys for the Array, with a total of 26 individuals recorded over ten surveys. Given their recorded abundance in the literature and recent site-specific surveys for the Array and nearby offshore wind farms, grey seals are considered likely to occur year-round within the Array marine mammal study area and regional marine mammal study area.
Designated sites
- The Array marine mammal study area does not overlap with any protected sites that have been designated for marine mammal features. Numerous sites have been identified as occurring within the vicinity of the regional marine mammal study area and are presented in greater detail in Apx. Table 8.2 and Apx Figure 8.6 Open ▸ . These include six Special Areas of Conservation (SACs) and one Marine Protected Area (MPA):
- Southern Trench MPA;
- Berwickshire and North Northumberland Coast SAC;
- Firth of Tay and Eden Estuary SAC;
- Isle of May SAC;
- Southern North Sea SAC;
- Moray Firth SAC; and
- Dornoch Firth and Morrich More SAC.
- The closest designated site is the Southern Trench MPA, which is situated 66.9 km from the site boundary and is designated for minke whales. All other sites are over 100 km from the site boundary.
- The LSE Screening Report will include a full screening of National and European designated sites with qualifying marine mammal interest features, that may be impacted by the Array. Any relevant sites and/or features screened into the marine mammal assessment will be assessed in the marine mammal chapter of the Array EIA Report. The information to support the assessment of transboundary European sites and features will be presented in the Report to Inform Appropriate Assessment (RIAA).
6.3.4. Potential Array ImpactsPotential Array Impacts
- A number of potential impacts which may occur during the construction, operation and maintenance, and decommissioning phases of the Array in the absence of designed in measures on marine mammals have been identified in Table 6.11 Open ▸ .
Table 6.11: Potential Impacts Identified for Marine Mammals in the Absence of Designed In Measures