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Appendix 9 Marine Mammals – Baseline Environment
9.1 Desktop Study
- An initial desk-based review of literature and data sources to support this Offshore EIA Scoping Report has identified a number of baseline datasets. These are summarised in Apx. Table 9. 1 Open ▸ .
- This report does not contain a detailed summary of the site-specific survey collected to support the development of the EIA Report, however has been issued to relevant consultees as a Marine Mammals Interim Data Report. The following section provides a detailed overview of other sources of data available for the Proposed Development. Details of site-specific data will be presented in the offshore EIA report.
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Baseline Characterisation
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Protected Areas
- There are several protected areas for marine mammals in east Scotland. Apx. Table 9. 2 Open ▸ provides an early indication of key designated sites that may occur in proximity to the Proposed Development and which may require consideration within the EIA and HRA. This list will be refined in the EIA to also include sites that fall within the potential zone of influence of the Proposed Development, which will be determined as part of the EIA process. A full screening of European sites with qualifying marine mammal interest features will be undertaken in the LSE Screening Report for the Proposed Development. Relevant marine mammal notified interest features of European sites screened into the marine mammal assessment will be fully considered and assessed in the ES section with the assessment on the European site itself deferred to the Report to Inform Appropriate Assessment (RIAA).
- The screening to be undertaken in the marine mammal ES section will also include national designations, including designated seal haul out sites, Sites of Special Scientific Interest (SSSIs) and Nature Conservation Marine Protected Areas (MPAs).
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Protected Areas
9.3.2 Below MLWS
9.3.2.1 Harbour Porpoise
- The most recent assessment of harbour porpoise in UK waters concluded that the overall trend in Conservation Status was Unknown, highlighting that there was insufficient data to establish a trend for the population size nor potential future prospects for the population (JNCC 2019b). The Proposed Development is located within the North Sea MU for harbour porpoise (IAMMWG, 2021), which is estimated to have an abundance of 346,601 porpoise (CV: 0.09, 95% CI: 289,498 – 419,96) based on estimates from the Small Cetaceans in the European Atlantic and North Seas (SCANS) III survey (Hammond et al., 2017;, Hammond et al., 2021). The SCANS III density estimate for the relevant survey block (Block R) was estimated to be 0.599 porpoise/ km2 (CV: 0.287).
- Given the sightings recorded thus far during the ongoing site specific aerial surveys, and from previous surveys in the Firth of Forth Round 3 Zone (Apx. Figure 9. 1 Open ▸ ), harbour porpoise are therefore considered likely to occur year round within the Proposed Development zone of potential impact.
- Minke Whale
- The most recent assessment of minke whales in UK waters concluded that the overall trend in Conservation Status was Unknown, highlighting that there was insufficient data to establish a trend for the population size nor potential future prospects for the population (JNCC, 2019f). All minke whales in UK waters are considered to be part of the Celtic and Greater North Seas MU (IAMMWG, 2021), which is estimated to have an abundance of 20,118 whales (CV: 0.18, 95% CI: 14,061 – 28,786) based on estimates from the SCANS III survey (Hammond et al., 2017; Hammond et al., 2021) and the ObSERVE survey (Rogan et al., 2018). The SCANS III density estimate for the relevant survey block (Block R) was estimated to be 0.0387 whales/ km2 (CV: 0.614).
- Given the sightings recorded thus far during the ongoing site specific aerial surveys, and from previous surveys in the Firth of Forth Round 3 Zone (Apx. Figure 9. 2 Open ▸ ), minke whales are considered likely to occur in the summer months within the Proposed Development zone of potential impact.
- White Beaked Dolphin
- The most recent assessment of white-beaked dolphins in UK waters concluded that the overall trend in Conservation Status was Unknown, highlighting that there was insufficient data to establish a trend for the population size nor potential future prospects for the population (JNCC, 2019e). All white-beaked dolphins in UK waters are considered to be part of the Celtic and Greater North Seas MU (IAMMWG, 2021), which has an estimated population size of 43,951 dolphins (CV: 0.22, 95% CI: 28,439 – 67,924) based on estimates from the SCANS III survey (Hammond et al., 2017; Hammond et al., 2021) and the ObSERVE survey (Rogan et al., 2018). The SCANS III density estimate for the relevant survey block (Block R) was estimated to be 0.243 dolphins/ km2 (CV: 0.484).
- Given the sightings recorded thus g the site specific aerial surveys, and from previous surveys in the Firth of Forth Round 3 Zone (Apx. Figure 9. 3 Open ▸ ), white-beaked dolphins are considered likely to occur year round (with increased numbers in the summer months) within the Proposed Development zone of potential impact.
9.3.2.4 Bottlenose Dolphin
- The most recent assessment of bottlenose dolphins in UK waters concluded that the overall trend in Conservation Status was Unknown, highlighting that although the population size appears to be stable, there were too few datapoints to confidently conclude on the current and future population trends (JNCC, 2019a).
- The Moray Firth population of bottlenose dolphins is the only known remaining resident population in the North Sea and it was for this reason that the Moray Firth SAC was established in order to protect this population. The current population estimate of bottlenose dolphin abundance for the Coastal East Scotland MU population is 195 individuals (95% Highest Posterior Density Intervals (HPDI): 162 to 253) based on photo-ID counts between 2006 and 2007 (Cheney et al., 2013). The results of further surveys suggest that the east coast Scotland population has continued to increase in size since 2007 (Cheney et al., 2018).
- The SCANS III density estimate for the relevant survey block (Block R) was estimated to be 0.0298 dolphins/ km2 (CV: 0.861). Within the Moray Firth SAC, bottlenose dolphins are generally found close to shore (within 3 km) and in shallow water (<20 m) (NatureScot, 2021). Their distribution outside of the SAC, along the of the Tayside and Fife coast, is similar, with dolphins mainly encountered in waters less than 20 m deep and within 2 km from the coast (Quick et al., 2014). Given the presence of bottlenose dolphins within coastal waters in east Scotland, they are considered likely to occur year-round in the coastal waters of the Proposed Development zone of potential impact.
- Grey Seals
- The most recent assessment of grey seals in UK waters concluded that the overall trend in Conservation Status was Favourable, with an overall trend in Conservation Status assessed as Improving (JNCC 2019c).
- Grey seal August haul-out counts in the East Scotland MU have been much higher than harbour seal counts. Though surveyed less frequency, overall counts for the East Scotland MU have shown an increase in grey seals from 2,328 in the 1996-1997 period to 3,683 in the 2016-2019 period. The counts at the East Scotland MU therefore account for 9% of the grey seals hauled-out in Britain and 14% of the grey seals hauled-out in Scotland between 2016-2019. In the Northeast England MU, grey seals are primarily present in the Northumberland area. While counts of this area are infrequent, they do show a significant increase in counts from 613 grey seals in the 1996-1997 period to 6,501 in the 2016-2019 period (SCOS, 2021). The total August haul-out count grey seals in the Northeast England MU in the count period 2016-2019 was 6,501 grey seals, which accounts for 15% of the grey seals hauled-out in Britain between 2016-2019 (SCOS, 2021).
- Telemetry data have shown that grey seals travel further to forage and between haul-out sites than harbour seals. Grey seals typically forage within 100 km of a haul-out site and foraging trips can last for 30 days; however, individual tracks have shown that some grey seals can make trips several hundred kilometres offshore (SCOS, 2021). In total, 46 adult grey seals have been tagged in the East Scotland MU between 1990 and 2013, and a further 23 have been tagged in the Northeast England MU between 1991 and 2008. Grey seals tracks have been recorded throughout the Study Area. The data show wide ranging behaviour, with individual grey seals tagged in the East Scotland MU and recording telemetry data within the Study Area, also recording telemetry tracks as far as the Outer Hebrides and Denmark (Apx. Figure 9. 6 Open ▸ ). The 59 adult grey seals with telemetry track data within the Study Area also showed connectivity with several UK grey seal SACs: the Berwickshire and North Northumberland Coast SAC, the Isle of May SAC, the Faray and Holm of Faray SAC, the Humber Estuary SAC, the North Rona SAC and the Monach Islands SAC.
- Given the sightings recorded thus far during the ongoing site specific aerial surveys, from previous surveys in the Firth of Forth Round 3 Zone (Apx. Figure 9. 4 Open ▸ ), from the seal habitat preference map (Apx. Figure 9. 5 Open ▸ ) and the telemetry data (Apx. Figure 9. 6 Open ▸ ), grey seals are considered likely to occur year round within the Proposed Development zone of potential impact.
9.3.2.6 Harbour Seals
- In the UK, harbour seals have been assessed as having an Unfavourable – Inadequate conservation status (JNCC 2019d). The assessment concluded Unfavourable – Inadequate for population size as the short-term trend is unknown and the current population size is below the Favourable Reference Range. In addition, the future prospects were assessed as Unfavourable – Inadequate because the future prospects of the population are poor.
- The Project is located within the East Scotland seal MU. Not all sites within the East Scotland MU are surveyed annually, however annual counts have been conducted in the Firth of Tay and Eden Estuary SAC on an annual basis since 2005. The SAC counts were stable between 1990 and 2002; however, after the 2002 PVD epidemic, counts declined rapidly and monotonically between 2002 and 2017 at a rate of -18.6% p.a. (Thompson et al., 2019) with no signs of recovery in recent years. Though surveyed with less frequency, overall counts for the East Scotland MU have also shown a decline since the 1996-1997 count period from 764 seals to 343 in the 2016-2019 count period (SCOS, 2021). All sites within the Tees Estuary (Northeast England MU) have been surveyed annually between 1996 and 2019 by the Industry Nature Conservation Agency (INCA), and, additionally, SMRU have carried out surveys in the wider MU in 1997, 2005, 2007, 2008, 2015, 2016 and 2018. Harbour seal August haul-out counts in the Northeast England MU are low, with annual counts ranging between 38 and 91. The most recent haul-out count is 79 harbour seals for the 2016-2019 count period (SCOS, 2021).
- Harbour seals typically forage within 40-50 km from their haul-out sites (compared to >100 km for grey seals) (SCOS, 2021). In total, 46 adult harbour seals have been tagged in the East Scotland MU between 2001 and 2017. Of the 46 adult harbour seals tagged in East Scotland, 25 had telemetry track data recorded within the Study Area (Apx. Figure 9. 8 Open ▸ ). All 25 of these harbour seals also showed connectivity with the Firth of Tay and Eden Estuary SAC. Only two of the 25 harbour seals tagged in the East Scotland MU recorded telemetry data out with the East Scotland MU, with both seals recording telemetry tracks within the Northeast England MU. No harbour seals have been tagged in the Northeast England MU.
- Given the sightings recorded during the site-specific aerial surveys, from previous surveys in the Firth of Forth Round 3 Zone (Apx. Figure 9. 4 Open ▸ ), from the seal habitat preference map (Apx. Figure 9. 7 Open ▸ ), and the telemetry data (Apx. Figure 9. 8 Open ▸ ), harbour seals are considered likely to occur year round (primarily in coastal waters) within the Proposed Development zone of potential impact.
9.3.3 Above MLWS
- The only marine mammal receptors that are at risk of impacts above MLWS are seals at hauled-out sites. Seal haul-out sites will be important to consider in terms of the potential impacts from landfall activities.
- There are three grey seal haul-out sites that are located within 10 km from ECC landfall locations: Long Craigs (~7 km), Scart Rock (~6 km), and Black Bull (~7 km). In the East Scotland MU there are three designated seasonal haul-out sites for grey seals: Fast Castle, Inchkeith and Craigleith. The closest of these designated seasonal haul outs is Fast Castle, which is located within 3 km of the landfall.
- There are no harbour seal haul-out sites near the ECC landfall locations, the nearest harbour seal haul-out site is Eastern Craigs, Black Rocks, Leith, which is located ~50 km swimming distance from the nearest ECC landfall location There are also two designated haul-out sites for harbour seals: Kinghorn Rocks and Inchmickery and Cow and Calves, both of which are located >40 km from ECC landfall location.