Vessel Collision Risk

An increase in vessel activity, compared to baseline levels, during the construction phase, may result in increased vessel collisions with marine mammals. The extent of this potential disturbance will be spatially restricted to within the boundaries of the Proposed Development and along routes to local ports. Beyond this, the movements of vessels using already established vessel routes will be dispersed and will become part of the background vessel traffic.

Harbour Porpoise

The construction of the Proposed Development is likely to result in a relatively small increase in vessel traffic compared to current background levels. Two of the key factors that determine the risk of a collision are the presence of marine mammals and vessels in the same area and whether those animals are exposed to vessels on a regulator basis (see Schoeman et al., 2020). As there is only a small increase in vessels against a baseline of high shipping activity, the likelihood of collisions occurring between vessels and marine mammals is considered to be low, with marine mammals likely to maintain their distance. There is therefore considered to be little potential for the increased vessel activity during construction to result in a significant impact to harbour porpoise in terms of collision risk with vessels. As such, no LSEs are anticipated to occur to harbour porpoise qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for harbour porpoise.

Bottlenose Dolphin

As discussed for harbour porpoise above, the increase in vessel traffic associated with the construction of the Proposed Development is likely to be low compared to background levels and likelihood of the impact occurring is considered to be low and there is therefore considered to be little potential for the increased vessel activity during construction to result in a significant impact to bottlenose dolphin in terms of collision risk with vessels. As such, no LSEs are anticipated to occur to bottlenose dolphin qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for bottlenose dolphin.

Harbour Seal

As discussed previously for underwater noise from piling, the usage of the Proposed Development by harbour seal is predicted to be low and there are no haul out sites within 40 km of either landfall option. As discussed for harbour porpoise, the increase in vessel traffic associated with the construction of the Proposed Development is likely to be low compared to background levels and likelihood of the impact occurring is considered to be low and there is therefore considered to be little potential for the increased vessel activity during construction to result in a significant impact to harbour seal in terms of collision risk with vessels. As such, no LSEs are anticipated to occur to harbour seal qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for harbour seal.

Grey Seal

As discussed previously, site-specific and desktop data sources indicate an overlap between grey seal movements and the Proposed Development as well as connectivity with the two European sites screened into the assessment of LSE (Isle of May SAC and the Berwickshire and North Northumberland Coast SAC). There are also grey seal haul outs, associated with the Berwickshire and North Northumberland Coast SAC in close proximity to the landfall options. The majority of vessels associated with construction of the Proposed Development will, however, be slow moving or stationary within the Proposed Development array area. Further, as only seals at the surface would be suspectable to vessel strike and given the limited number of vessels operating at any one time, not all grey seals in the Proposed Development array area would be simultaneously at risk of collision. The Advice on Operations for the SACs screened in (e.g. Natural England and NatureScot, 2021) identify collision risk for grey seal, however the text draws on the risk of corkscrew injuries from vessels which is no longer considered to be an impact associated with vessel movements (Brownlow et al., 2016; Bishop et al., 2016). The Advice on Operations acknowledges that in general instances of injury or mortality of grey seals caused by vessels remains a very rare occurrence in UK waters (Natural England and NatureScot, 2021).
The increase in vessel traffic associated with the construction of the Proposed Development is likely to be low compared to background levels and likelihood of the impact occurring is considered to be low and there is therefore considered to be little potential for the increased vessel activity during construction to result in a significant impact to grey seal in terms of collision risk with vessels. As such, no LSEs are anticipated to occur to grey seal qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for grey seal.

Changes in Prey Availability

There is the potential for changes in marine mammal prey abundance and distribution to arise as a result of construction activities which physically disturb the seabed, result in increased SSC or which generate underwater noise. Potential impacts to prey species may result in changes in the ability/success of marine mammals to forage in the area of the Proposed Development. Key prey species for marine mammals include clupeids (e.g. herring), gadoids (e.g., cod, whiting), sandeels and flatfish. These species are important components of the fish community in the vicinity of the Proposed Development (SSE, 2020b).

Harbour Porpoise

The widest ranging effect on prey species is likely to be underwater noise during construction. Harbour porpoise have a large foraging range and any impact to the fish community in the vicinity of the Proposed Development will be of short-term duration and temporary in nature. The effect of underwater noise on prey species can however only be fully assessed using the results of project-specific underwater noise modelling which will be undertaken for the EIA. Until these results are available, this impact cannot be screened out for harbour porpoise.

Bottlenose Dolphin

St Andrews Bay and the Tay estuary are consistently used by approximately half of the estimated Moray Firth SAC bottlenose dolphin population during the summer, but bottlenose dolphin presence in this area is focused on the entrance to the Firth of Tay and waters around Montrose (Arso Civil et al., 2019). The Moray Firth bottlenose dolphin population predominantly occurs in coastal areas (SSE, 2012) and therefore, any potential temporary changes to the fish community in the vicinity of the Proposed Development array area as a result of construction impacts such as underwater noise, are unlikely to result in significant effects to bottlenose dolphin given the potential for foraging opportunities in the wider area. The effect of underwater noise on prey species can however only be fully assessed using the result of project-specific underwater noise modelling which will be undertaken for the EIA. Until these results are available, this impact cannot be screened out for further consideration for bottlenose dolphin.

Harbour Seal

As discussed previously, and shown in Figure 5.1, harbour seal usage of the Proposed Development is predicted to be low and the area is considered unlikely to be an important foraging area for this species. Whilst effects on fish populations from underwater noise, SSC and habitat disturbance are likely to be temporary, localised, short-term and therefore not significant, the effect of underwater noise on prey species will be assessed using the result of project-specific underwater noise modelling which will be undertaken for the EIA. Until these results are available, this impact cannot be screened out for harbour seal.

Grey Seal

The Proposed Development is likely to overlap with foraging grounds for grey seal (see Figure 5.1 and Appendix 2) from both the Berwickshire and North Northumberland Coast SAC and the Isle of May SAC. Effects on fish populations from underwater noise, SSC and habitat disturbance are likely to be temporary, localised, short-term and therefore not significant. The effect of underwater noise on prey species will, however, be assessed using the result of project-specific underwater noise modelling which will be undertaken for the EIA. Until these results are available, this impact cannot be screened out for grey seal.

Changes in Water Clarity

Sediment disturbance arising from construction activities (e.g. foundation and cable installation, and seabed preparation works) may result in temporary increases in SSC which can directly impact the foraging ability of marine mammals. Indirect effects may also occur as a result of impacts to prey species from SSC (these are considered under ‘changes to prey availability’ above). The extent of this impact will be spatially restricted to within the boundaries of the Proposed Development and the surrounding area (which will be refined through physical processes modelling to be undertaken for the EIA).

Harbour Porpoise

Harbour porpoise are well known to forage in tidal areas where water conditions are turbid and visibility conditions poor. For example, harbour porpoise in the UK have been documented foraging in areas with high tidal flows (e.g. Pierpoint 2008; Marubini et al., 2009); therefore, low light levels, turbid waters and suspended sediments are unlikely to adversely impact harbour porpoise foraging success. When the visual sensory systems of odontocetes are compromised, they are able to sense the environment in other ways, primarily using echolocation to navigate and find food in darkness for example. There is likely to be large natural variability in the SSC within the Proposed Development Marine Mammal Study Area due the proximity to the Firth of Forth estuary, so marine mammals living here are likely to be tolerant of any small scale increases, such as those associated with the construction activities. This impact is therefore screened out of further consideration for harbour porpoise.

Bottlenose Dolphin

As above for harbour porpoise, bottlenose dolphins are adapted to, and tolerant of, turbid environments. The localised and short-term nature of increases in SSC during the construction phase are unlikely to result in a significant effect on the foraging ability of this species. This impact is therefore screened out of further consideration for bottlenose dolphin.

Harbour Seal

Harbour seal are well known to forage in turbid waters with poor visibility and, in the UK, have been documented foraging in areas with high tidal flows (e.g. Hastie et al., 2016). Low light levels, turbid waters and suspended sediments are unlikely to adversely impact harbour seal foraging success. When the visual sensory systems of harbour seal are compromised, they are able to detect water movements and hydrodynamic trails with their mystacial vibrissae. Any localised and short-term increases in SSC are considered unlikely to result in significant effects on the foraging ability of harbour seal and therefore this impact is screened out of further consideration for this species.

Grey Seal

Grey seal frequently occur in turbid environments and are adapted to navigating and locating prey in such conditions (Todd et al., 2014). The temporary increases in SSC that may arise during the construction and decommissioning phases will be localised, short-term and intermittent and unlikely to result in significant effects to the foraging ability of grey seal. This impact is therefore screened out of further consideration for grey seal.

Accidental Pollution

All Species

There is the potential for pollution to be accidentally released during the construction phase of the Proposed Development from vessels/vehicles and equipment/machinery. The risk of such events occurring will be managed by the implementation of measures set out in standard post consent plans (e.g. a PEMMP including a Marine Pollution Contingency Plan) which will be implemented as part of the Proposed Development. These plans will include planning for accidental spills, address all potential contaminant releases and include key emergency contact details. These plans will also set out industry good practice and OSPAR, IMO and MARPOL guidelines for preventing pollution at sea. With reference to these plans, a significant impact within the extent of the Proposed Development is considered very unlikely to occur, and a major incident that may impact any species at a population level is considered very unlikely. Furthermore, in their response to the LSE Screening Report for the initial Berwick Bank Wind Farm Proposal, MSS and MS-LOT recommended that this impact could be screened out. On this basis, accidental pollution is screened out of further consideration for all species, across all phases of the Proposed Development.

Operation and Maintenance Phase

Underwater Noise from Vessels and Other Vessel Activities

Disturbance of marine mammals may arise during the operation and maintenance phase from increased vessel traffic and vessel-based activities (e.g. cable reburial etc.) associated with operation and maintenance activities. As during the construction phase, the extent of this potential disturbance will be spatially restricted to within the boundaries of the Proposed Development and along routes to local ports. Beyond this, the movements of vessels using already established vessel routes will be dispersed and will become part of the background vessel traffic.

Harbour Porpoise

The nearest SAC for harbour porpoise (Southern North Sea SAC) is located 146 km to the south of the Proposed Development array area. The operation and maintenance port location for the Proposed Development is not confirmed at this stage but it is likely that the majority of vessel movements will be to/from the east coast of Scotland. It is considered that vessel traffic and vessel-based activities associated with the operation and maintenance phase will not result in significant disturbance to harbour porpoise therefore this impact is screened out of further consideration for this species.

Bottlenose Dolphin

The nearest SAC for bottlenose dolphin is the Moray Firth SAC, located 224 km to the north west of the Proposed Development array area and bottlenose dolphin use of the Proposed Development array area is likely to be low. The small uplift in vessel activity during the operation and maintenance phase, compared to the baseline levels, is unlikely to result in a significant disturbance to bottlenose dolphin. Furthermore, as discussed in paragraph 245, the east coast bottlenose dolphin population is primarily distributed along the east coast from the Moray Firth to the north of the Firth of Forth and the species is mainly encountered in inshore areas. Any disturbance associated with activities near shore would be short term and the baseline suggests that bottlenose dolphin is unlikely to occur along this part of the coast. This impact is therefore screened out of further consideration for this species.

Harbour Seal

The usage of the Proposed Development by harbour seal is predicted to be low and there are no haul out sites near either landfall option which could be disturbed by vessels involved in maintenance activities along the Proposed Development offshore cable corridor. The location of ports to be used in support of the Proposed Development is not currently confirmed, although it is likely that the majority of vessel movements will be to/from local ports on the east coast of Scotland. Should operation and maintenance ports be located within the Firth of Tay then there is the potential for interaction between vessel movements and harbour seals using the Firth of Tay (see Appendix 2). There is therefore the potential for vessel movements and vessel-based operation and maintenance activities to result in disturbance to the harbour seal feature of the Firth of Tay and Eden Estuary SAC.

Grey Seal

Data indicate an overlap of grey seal movements and the Proposed Development and potential connectivity with the two European sites screened into the assessment of LSE (Isle of May SAC and the Berwickshire and North Northumberland Coast SAC). There is the potential for vessel movements associated with the operation and maintenance of the Proposed Development to result in disturbance to grey seal foraging in the Proposed Development array area and also to grey seal at haul out sites located in the close vicinity of the proposed ECC landfall options (i.e. within 2 km of the Thorntonloch Landfall, and ~5.5 km from the Skateraw Landfall; Figure 5.2). There is therefore considered to be the potential for vessel movements during the operation and maintenance phase and vessel-based operation and maintenance activities to result in a disturbance to grey seals.

Vessel Collision Risk

An increase in vessel activity associated with operation and maintenance activities may result in increased collisions with marine mammals. The extent of this potential disturbance will be spatially restricted to within the boundaries of the Proposed Development and along routes to local ports. Beyond this, the movements of vessels using already established vessel routes will be dispersed and will become part of the background vessel traffic.

Harbour Porpoise

The operation and maintenance of the Proposed Development is likely to result in a relatively small increase in vessel traffic compared to current background levels, and the majority of vessels associated with operation and maintenance activities are likely to be slow moving or stationary within the Proposed Development array area. The likelihood of collisions occurring between vessels and marine mammals is considered to be low and there is therefore considered to be little potential for the increased vessel activity during operation and maintenance activities to result in a significant impact to harbour porpoise in terms of collision risk with vessels. As such, no LSEs are anticipated to occur on harbour porpoise qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for this species.

Bottlenose Dolphin

The increase in operation and maintenance vessel traffic is likely to be low compared to background levels, and the majority of vessels associated with operation and maintenance activities will be slow moving or stationary within the Proposed Development array area. The likelihood of a collision occurring is considered to be low and therefore the increased vessel activity during operation and maintenance is unlikely to result in a significant impact to bottlenose dolphin in terms of collision risk with vessels. As such, no LSEs are anticipated to occur on bottlenose dolphin qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for this species.

Harbour Seal

Usage of the Proposed Development by harbour seal is predicted to be low and there are no haul out sites within 40 km of either landfall option. The increase in operation and maintenance vessel traffic is likely to be low compared to background levels, and the majority of vessels associated with operation and maintenance activities will be slow moving or stationary within the Proposed Development array area. The likelihood of a collision occurring is considered to be low and therefore the increased vessel activity during operation and maintenance is unlikely to result in a significant impact to harbour seal in terms of collision risk with vessels. No LSEs are anticipated to occur on harbour seal qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for this species.

Grey Seal

Existing data sources indicate an overlap between grey seal movements and the Proposed Development, as well as connectivity with the two European sites screened into the assessment of LSE (Isle of May SAC and the Berwickshire and North Northumberland Coast SAC). There are also grey seal haul outs in close proximity to the landfall options. The Advice on Operations for the SACs (e.g. Natural England and NatureScot, 2021) screened in identify collision risk for grey seal, however the text draws on the risk of corkscrew injuries from vessels which is no longer considered to be an impact associated with vessels (Brownlow et al., 2016; Bishop et al., 2016). The Advice on Operations acknowledges that in general instances of injury or mortality of grey seals caused by vessels remains a very rare occurrence in UK waters (Natural England and NatureScot, 2021).
The increase in vessel traffic associated with the operation and maintenance of the Proposed Development is likely to be low compared to background levels and likelihood of the impact occurring is considered to be low and there is therefore considered to be little potential for the increased vessel activity to result in a significant impact to grey seal in terms of collision risk with vessels. As such, no LSEs are anticipated to occur to grey seal qualifying features of any European site and the impact of vessel collision risk is therefore screened out of further consideration for grey seal.

Changes in Prey Availability

There is the potential for changes in marine mammal prey abundance and distribution to arise as a result of operation and maintenance activities and as a result of the presence of offshore structures. The potential for any adverse effects on prey are, however, significantly reduced compared to the construction phase as underwater noise will be substantially lower.

Harbour Porpoise

Harbour porpoise have a large foraging range and significant impacts to the fish communities in the vicinity of the Proposed Development during operation and maintenance activities are considered highly unlikely due to the reduced magnitude of any potential impact. In their response to the LSE Screening Report for the initial Berwick Bank Wind Farm Proposal (a smaller project), MSS and MS-LOT recommended that this impact be screened in for the operation and maintenance phase. On this basis, there is considered to be the potential for LSE from changes in prey availability on the harbour porpoise feature of the Southern North Sea SAC. All other European sites with harbour porpoise as features are located more than 292 km from the Proposed Development and so a significant effect occurring to features of these sites is considered highly unlikely and all other European sites for harbour porpoise are screened out.

Bottlenose Dolphin

The use of the Proposed Development by bottlenose dolphin is predicted to be low and the Moray Firth bottlenose dolphin population predominantly occurs in coastal areas (SSE, 2012). Significant impacts to the fish communities in the vicinity of the Proposed Development during operation and maintenance activities are considered highly unlikely due to the reduced magnitude of any potential impact and therefore significant effects to bottlenose dolphin from changes in prey abundance or distribution are also considered unlikely. As above for harbour porpoise, MSS and MS-LOT have however recommended that this impact be screened in for the operation and maintenance phase. On this basis, there is considered to be the potential for LSE from changes in prey availability on the bottlenose dolphin feature of the Moray Firth SAC.

Harbour Seal

Harbour seal usage of the Proposed Development is predicted to be low and the area is considered unlikely to be an important foraging area for this species. Significant effects on prey species during operation and maintenance activities are not anticipated and are therefore unlikely to result in a significant effect for harbour seal. As above for harbour porpoise, MSS and MS-LOT have however recommended that this impact be screened in for the operation and maintenance phase. On this basis, there is considered to be the potential for LSE from changes in prey availability on the harbour feature of the Firth of Tay and Eden Estuary SAC.

Grey Seal

The Proposed Development is likely to overlap with foraging grounds for grey seal (see Figure 5.1 and Appendix 2) from both the Berwickshire and North Northumberland Coast SAC and the Isle of May SAC. Effects on fish populations during the operation and maintenance phase will be less than during construction and are not expected to be significant, therefore, significant effects on harbour seal are considered unlikely. As above for harbour porpoise, MSS and MS-LOT have however recommended that this impact be screened in for the operation and maintenance phase. On this basis, there is considered to be the potential for LSE from changes in prey availability on the grey seal feature of the Berwickshire and North Northumberland Coast SAC and Isle of May SAC.

Operational Noise

The MMO (2014) review of post-consent monitoring at offshore wind farms in the UK and elsewhere in Europe showed that noise levels from operational wind turbines are low and the spatial extent of the potential impact on marine mammals is generally estimated to be small, with behavioural responses only likely at ranges close to wind turbines.

Harbour Porpoise

Although harbour porpoise are likely to be present throughout the Proposed Development, several published studies provide evidence that they are not likely to be displaced from operational wind farms. At the Horns Rev and Nysted offshore wind farms in Denmark, long-term monitoring demonstrated that harbour porpoise were sighted regularly within the operational offshore wind farms, and within two years of operation, the populations had returned to levels that were comparable with the wider area (Diederichs et al., 2008). Similarly, a monitoring programme at the Egmond aan Zee offshore wind farm in the Netherlands reported significantly more harbour porpoise activity in the offshore wind farm during the operational phase compared to the reference area (Scheidat et al., 2011). Other studies at Dutch and Danish offshore wind farms (Lindeboom et al., 2011) also suggest that harbour porpoise may be attracted to increased foraging opportunities within operating offshore wind farms. Other reviews have also concluded that operational wind farm noise will have negligible effects (Madsen et al., 2006; Teilmann et al., 2006a; Teilmann et al., 2006b; CEFAS 2010; Brasseur et al., 2012). There is therefore considered to be no potential for LSE as a result of wind turbine noise during the operation and maintenance phase and this impact is screened out of further consideration for this species.

Bottlenose Dolphin

Noise levels from operational wind turbines are predicted to be low and the spatial extent of any potential behavioural impact to bottlenose dolphin will be small. Given the low abundance of bottlenose dolphin within the Proposed Development array area there is considered to be no potential for LSE as a result of wind turbine noise during the operation and maintenance phase and this impact is screened out of further consideration for this species.

Harbour Seal

Several published studies provide evidence that harbour seals are unlikely to be displaced from operational wind farms. At the Horns Rev and Nysted offshore wind farms in Denmark, long-term monitoring showed that harbour seals were sighted regularly within the operational offshore wind farms, and within two years of operation, the populations had returned to levels that were comparable with the wider area (Diederichs et al., 2008). In addition, recent tagging work has shown that some harbour seals demonstrated grid-like movement patterns as these animals moved between individual wind turbines at operational wind farms, strongly suggesting these structures are used to support foraging (Russell et al., 2014; Russel et al., 2016). The use of the Proposed Development by harbour seal is also likely to be low. There is therefore considered to be no potential for LSE on harbour seal as a result of wind turbine noise during the operation and maintenance phase, and this impact is screened out of further consideration for this species.

Grey Seal

As for harbour seal, grey seal are considered unlikely to be displaced from the Proposed Development array area during the operational phase. Tagging work by Russell et al., (2014) found that some tagged grey seals demonstrated grid-like movement patterns as these animals moved between individual wind turbines, suggesting the use of wind turbines by grey seal to support foraging. There is therefore considered to be no potential for LSE on grey seal as a result of wind turbine noise during the operation and maintenance phase, and this impact is screened out of further consideration for this species.

EMF

All Species

The presence of subsea electrical cabling has the potential to emit a localised EMF. Based on the data available to date, there is no evidence of EMF related to marine renewable devices having any impact (either beneficial or adverse) on marine mammals (Copping, 2018). There is no evidence that seals can detect or respond to EMF, however some species of cetaceans may be able to detect variations in magnetic fields (Normandeau et al., 2011). To date, the only marine mammal known to show any response to EMF is the Guiana dolphin Sotalia guianensis which has been shown to possess an electroreceptive system, which uses the vibrissal crypts on their rostrum to detect electrical stimuli similar to those generated by small to medium sized fish (Czech-Damal et al., 2013). However, this has not been shown in any other species of marine mammal and this species does not occur within the Proposed Development. The impact of EMF on all marine mammal features of European sites is, therefore, screened out of further consideration.

Accidental Pollution

All Species

The potential for LSE on Annex II marine mammal features of European sites as a result of accidental pollution can be discounted at this stage and is therefore screened out. The justification is as presented previously in section 5.4.3 – Construction Phase: Accidental Pollution.

Decommissioning Phase

The impacts during the decommissioning phase are considered to be similar and potentially less than those outlined above in the construction phase (section 5.4.3 – Construction Phase).

5.4.4. Determination of LSE for Marine Mammals

Table 5.10 Open ▸ to Table 5.15 Open ▸ presents the results of the LSE determination assessment as a result of the Proposed Development on relevant qualifying interest features of the European sites identified for marine mammals. Separate LSE screening tables are presented for each of the UK sites and a single table ( Table 5.15 Open ▸ ) has been produced to cover the 19 transboundary sites screened into the LSE assessment for harbour porpoise. This is because the justifications for the screening decisions were the same for all of the transboundary sites on the basis of the distance of these sites from the Proposed Development.
These assessments have been made in the absence of mitigation measures. The footnotes to these tables provide a brief assessment to support the screening in or out of each of these likely significant effects on the identified SAC features. Where effects are not applicable to a particular feature they are greyed out.

Likely Significant Effects in combination

The LSE test requires consideration of the Proposed Development alone and/ or in-combination with other plans and projects. Therefore, it is not necessary at the LSE stage to consider sites/features for which an LSE ‘alone’ has already been identified, as in-combination effects will be considered at the Appropriate Assessment. The focus at this stage should be to identify sites/features for which no LSE alone was concluded, but for which there is potential for a LSE in-combination to occur in combination with other plans or projects(e.g. due to wide foraging ranges resulting in a species interacting with a large number of projects).
Given the highly precautionary method for site selection applied during this Screening assessment, it is considered that the consolidation of information regarding external plans and projects would not likely result in additional LSEs being identified for the Screening assessment. For marine mammals, the potential for LSE alone is identified for all UK sites within species range, therefore effects in-combination will be considered at Appropriate Assessment.
With respect to the 19 transboundary sites over the distances considered, all relevant effect-pathways are considered extremely weak, such that only a negligible (if even detectable) effects would be apparent. Such effects are considered to be negligible and could not contribute in any material way to an in-combination effect and as such, in-combination effects associated with planned projects or other activities in the vicinity of the Proposed Development are also not anticipated for the harbour porpoise feature of any transboundary site.

Table 5.10: LSE Matrix for Marine Mammal Features of the Berwickshire and North Northumberland Coast SAC

a: Underwater noise from piling, UXO clearance and pre-construction surveys – telemetry data indicates potential connectivity between the Proposed Development and this SAC. The Proposed Development is located 30.1 km from the site which is within the screening range of 100 km used for grey seal based on typical foraging ranges and so there is the potential for grey seal qualifying features of this SAC to occur within the zone of impact (injury and behavioural) from noise associated with piling during construction, UXO clearance activities and pre-construction surveys (e.g. geophysical surveys). There is therefore considered to be potential for LSE from underwater noise during construction.

b: Underwater noise from vessels and other vessel activities – available data indicate an overlap between grey seal movements and the Proposed Development, and potential connectivity between this SAC and the Proposed Development. There is therefore considered to be potential for LSE from vessel noise across all phases of the Proposed Development.

c: Vessel collision risk – the increase in vessel traffic associated with the construction, operation and maintenance and decommissioning of the Proposed Development is likely to be low compared to background levels and likelihood of the impact occurring is considered to be low and there is therefore considered to be little potential for the increased vessel activity across all phases to result in a significant impact to grey seal in terms of collision risk with vessels. It is therefore concluded that there is no potential for LSE from vessel collision risk across all phases of the Proposed Development.

d: Changes in prey availability – the majority of effects on fish populations across all phases of the Proposed Development are likely to be temporary, localised, short-term and not significant. The widest ranging effect will be underwater noise during construction, and impacts to prey species will be assessed using underwater noise modelling for the EIA. Given the likely importance of the Proposed Development as a foraging area for grey seal from this SAC, there is considered to be potential for LSE across all phases of the Proposed Development.

e: Changes in water clarity – grey seal frequently occur in turbid environments and are adapted to navigating and locating prey in such conditions. Increases in SSC during construction and decommissioning will be localised, short-term and intermittent and unlikely to result in significant effects to the foraging ability of grey seal. It is considered that there is no potential for LSE from changes in water clarity.

f: Operational noise – noise levels from operational wind turbines are predicted to be low and the spatial extent of any potential behavioural impact to grey seal will be small. Several published studies indicate that grey seal are not likely to be displaced from the operational wind farm and so there is considered to be no potential for LSE as a result of wind turbine noise during the operation and maintenance phase.

g: EMF – there is no evidence of EMF related to marine renewable devices having any impact (either beneficial or adverse) on marine mammals and there is no evidence that seals can detect or respond to EMF. It is concluded that there is no potential for LSE from EMF during the operation and maintenance phase.

h: Accidental pollution – a good practice approach will be implemented as part of the Proposed Development via post-consent plans (e.g. a PEMMP) to reduce potential impacts associated with accidental pollution events across all phases of the Proposed Development, irrespective of the possible effects on European sites. Following advice from NS (2021) and MSS (2021), accidental pollution associated with construction activities is not considered as an effect pathway because this will be subject to other regulatory control through both legislation and the requirements for contingency plans. This rationale is taken to apply to all phases of the Proposed Development and the potential for LSE is discounted.

i: In-combination effects - Activities associated with planned projects or other activities in the vicinity of the Proposed Development have the potential to result in LSE to Annex II grey seal features of the SAC as a result of in-combination effects across all phases of the Proposed Development. Where potential for LSE has been concluded alone, the potential for LSE has been concluded in-combination.

Table 5.11: LSE Matrix for Marine Mammal Features of the Isle of May SAC

a: Underwater noise from piling, UXO clearance and pre-construction surveys – telemetry data indicates potential connectivity between the Proposed Development and this SAC. The Proposed Development array area is located 38.5 km from the site which is within the screening range of 100 km used for grey seal based on typical foraging ranges and so there is the potential for grey seal qualifying features of this SAC to occur within the zone of impact (injury and behavioural) from noise associated with piling during construction, UXO clearance activities and pre-construction surveys (e.g. geophysical surveys). There is therefore considered to be potential for LSE from underwater noise during the construction phase.

b: Underwater noise from vessels and other vessel activities – available data indicate an overlap between grey seal movements and the Proposed Development, and potential connectivity between this SAC and the Proposed Development. Important haul out sites for grey seal are also in close proximity to the proposed ECC. There is therefore considered to be potential for LSE across all phases of the Proposed Development as a result of noise from vessels.

d: Changes in prey availability – the majority of effects on fish communities in the vicinity of the Proposed Development are anticipated to be temporary, localised, short-term and not significant. The widest ranging effect will be underwater noise during construction, and impacts to prey species will be assessed using underwater noise modelling for the EIA. Given the likely importance of the Proposed Development as a foraging area for grey seal from this SAC, there is considered to be potential for LSE across all phases of the Proposed Development.

i: In-combination effects - activities associated with planned projects or other activities in the vicinity of the Proposed Development have the potential to result in LSE to Annex II grey seal features of the SAC as a result of in-combination effects across all phases of the Proposed Development. Where potential for LSE has been concluded alone, the potential for LSE has been concluded in-combination.

Table 5.12: LSE Matrix for Marine Mammal Features of the Firth of Tay and Eden Estuary SAC

a: Underwater noise from piling, UXO clearance and pre-construction surveys – telemetry data indicates potential connectivity between the Proposed Development and this SAC. The Proposed Development is within the foraging range of harbour seal. There is therefore the potential for harbour seal features of this SAC to be within the zone of impact (injury and behavioural) from noise associated with piling during construction, UXO clearance activities and pre-construction surveys (e.g. geophysical surveys). There is therefore considered to be potential for LSE from underwater noise during the construction phase.

b: Underwater noise from vessels and other vessel activities - usage of the Proposed Development by harbour seal is predicted to be low and there are no haul out sites within 40 km of the landfall options which could be disturbed by vessel noise. The location of ports to be used in support of the Proposed Development is not, however, currently confirmed and should any ports be located within the Firth of Tay then there is the potential for interaction between vessels and harbour seals using the Firth of Tay. There is therefore considered to be the potential for LSE from underwater noise associated with vessel movements.

c: Vessel collision risk - the increase in vessel traffic associated with the construction, operation and maintenance and decommissioning of the Proposed Development is likely to be low compared to background levels and likelihood of the impact occurring is considered to be low and there is therefore considered to be little potential for the increased vessel activity across all phases to result in a significant impact to grey seal in terms of collision risk with vessels. It is therefore concluded that there is no potential for LSE from collision risk associated with vessel movements.

d: Changes in prey availability - the majority of effects on fish communities in the vicinity of the Proposed Development are anticipated to be temporary, localised, short-term and not significant. The widest ranging effect will be underwater noise during construction, and impacts to prey species will be assessed using underwater noise modelling for the EIA. There is therefore considered to be potential for LSE as a result of changes to prey availability across all phases of the Proposed Development.

e: Changes in water clarity – harbour seal frequently occur in turbid environments and are adapted to navigating and locating prey in such conditions. Increases in SSC during construction and decommissioning will be localised, short-term and intermittent and unlikely to result in significant effects to the foraging ability of harbour seal. It is considered that there is no potential for LSE from changes in water clarity.

f: Operational noise – noise levels from operational wind turbines are predicted to be low and the spatial extent of any potential behavioural impact to harbour seal will be small. Several published studies indicate that harbour seal are not likely to be displaced from the operational wind farm and so there is considered to be no potential for LSE as a result of wind turbine noise during the operation and maintenance phase.

i: In-combination effects - activities associated with planned projects or other activities in the vicinity of the Proposed Development have the potential to result in LSE to the Annex II harbour seal feature of the SAC as a result of in-combination effects across all phases of the Proposed Development. Where potential for LSE has been concluded alone, the potential for LSE has been concluded in-combination.

Table 5.13: LSE Matrix for Marine Mammal Features of the Southern North Sea SAC

a: Underwater noise from piling, UXO clearance and pre-construction surveys – there is considered to be the potential for harbour porpoise from this site to be present (i.e. transiting or foraging) within the Proposed Development and zone of potential impact (injury and behavioural) from underwater noise associated with piling, UXO clearance activities and pre-construction surveys (e.g. geophysical surveys). There is therefore considered to be potential for LSE from underwater noise during the construction phase.

b: Underwater noise from vessels and other vessel activities - given the distance of the site from the Proposed Development (>144 km) and that the majority of vessel movements across all phases of the Proposed Development will likely be to/from ports on the east coast of Scotland, it is considered that vessel traffic will not result in a significant disturbance to qualifying features of the site. The uplift in vessel traffic across all phases of the Proposed Development is also likely be low compared to current background levels. It is therefore concluded that there is no potential for LSE from vessel noise.

c: Vessel collision risk - the uplift in vessel traffic across all phases of the Proposed Development is considered to be low compared to current background levels and the advice on operations for this SAC (JNCC and Natural England, 2019) does not identify the pressure of death/injury by collision as a significant risk. The likelihood of collisions occurring between vessels and marine mammals is considered to be low. It is therefore concluded that there is no potential for LSE from vessel collision risk across all phases of the Proposed Development.

d: Changes in prey availability – the majority of effects on fish communities in the vicinity of the Proposed Development are anticipated to be temporary, localised, short-term and not significant. The widest ranging effect will be underwater noise during construction, and impacts to prey species will be assessed using underwater noise modelling for the EIA. There is however considered to be potential for LSE from changes to prey availability across all phases of the Proposed Development.

e: Changes in water clarity – harbour porpoise frequently occur in turbid environments and are adapted to navigating and locating prey in such conditions. Increases in SSC during construction and decommissioning will be localised, short-term and intermittent and unlikely to result in significant effects to the foraging ability of harbour porpoise. It is considered that there is no potential for LSE from changes in water clarity.

f: Operational noise – noise levels from operational wind turbines are predicted to be low and the spatial extent of any potential behavioural impact to harbour porpoise will be small. Several published studies indicate that harbour porpoise are not likely to be displaced from the operational wind farm and so there is considered to be no potential for LSE as a result of wind turbine noise during the operation and maintenance phase.

g: EMF – there is no evidence of EMF related to marine renewable devices having any impact (either beneficial or adverse) on marine mammals and there is no evidence to indicate that harbour porpoise respond to EMF. It is concluded that there is no potential for LSE from EMF during the operation and maintenance phase.

i: In-combination effects – Activities associated with planned projects or other activities in the vicinity of the Proposed Development have the potential to result in LSE to Annex II harbour porpoise feature of the SAC as a result of in-combination effects across all phases of the Proposed Development. Where potential for LSE has been concluded alone, the potential for LSE has been concluded in-combination.

Table 5.14: LSE Matrix for Marine Mammal Features of the Moray Firth SAC

a: Underwater noise from piling, UXO clearance and pre-construction surveys – there is the potential for bottlenose dolphin features of this site to be present (i.e. transiting or foraging) within the Proposed Development and zone of potential impact (injury and behavioural) from underwater noise associated with piling, UXO clearance activities and pre-construction surveys (e.g. geophysical surveys). There is therefore considered to be potential for LSE from underwater noise during the construction phase.

b: Underwater noise from vessels and other vessel activities - given the distance of the site from the Proposed Development (224 km from the array area), the low numbers of bottlenose dolphin likely to be present in the area and that the majority of vessel movements across all phases of the Proposed Development will likely be to/from ports on the east coast of Scotland, it is considered that vessel traffic will not result in a significant disturbance to qualifying features of the site. The uplift in vessel traffic across all phases of the Proposed Development is also likely be low compared to current background levels. It is therefore concluded that there is no potential for LSE from vessel noise.

d: Changes in prey availability - the majority of effects on fish communities in the vicinity of the Proposed Development are anticipated to be temporary, localised, short-term and not significant. The widest ranging effect will be underwater noise during construction, and impacts to prey species will be assessed using underwater noise modelling for the EIA. There is however considered to be potential for LSE from changes in prey availability across all phases of the Proposed Development.

e: Changes in water clarity – bottlenose dolphin frequently occur in turbid environments and are adapted to navigating and locating prey in such conditions. Increases in SSC during construction and decommissioning will be localised, short-term and intermittent and unlikely to result in significant effects to the foraging ability of this species. It is considered that there is no potential for LSE from changes in water clarity.

f: Operational noise – Noise levels from operational wind turbines are predicted to be low and the spatial extent of any potential behavioural impact to bottlenose dolphin will be small. Given the low abundance of bottlenose dolphin within the Proposed Development array area, there is considered to be no potential for LSE as a result of wind turbine noise during the operation and maintenance phase.

g: EMF – there is no evidence of EMF related to marine renewable devices having any impact (either beneficial or adverse) on marine mammals and there is no evidence to indicate that bottlenose dolphin respond to EMF. It is concluded that there is no potential for LSE from EMF during the operation and maintenance phase.

h: Accidental pollution – a good practice approach will be implemented as part of the Proposed Development via post-consent plans (e.g. a PEMMP) to reduce potential impacts associated with accidental pollution events across all phases of the Proposed Development irrespective of the possible effects on European sites. Following advice from NS (2021) and MSS (2021), accidental pollution associated with construction activities is not considered as an effect pathway because this will be subject to other regulatory control through both legislation and the requirements for contingency plans. This rationale is taken to apply to all phases of the Proposed Development and the potential for LSE is discounted.

f: In-combination effects – Activities associated with planned projects or other activities in the vicinity of the Proposed Development have the potential to result in LSE to Annex II bottlenose dolphin feature of the SAC as a result of in-combination effects across all phases of the Proposed Development. Where potential for LSE has been concluded alone, the potential for LSE has been concluded in-combination.

Table 5.15: LSE Matrix for the 19 Transboundary Harbour Porpoise Sites

a: Underwater noise from piling, UXO clearance and pre-construction surveys - given the significant distance of the nearest transboundary site to the Proposed Development (closest site is located 292 km from the array area), the Proposed Development is unlikely to constitute important foraging grounds for individuals from these sites and underwater noise during construction is unlikely to result in significant effects (disturbance or injury) on the harbour porpoise features of these sites. It is therefore concluded that there is no potential for LSE on the Annex II harbour porpoise feature of any transboundary site during the construction phase from piling, UXO clearance activities or pre-construction surveys (e.g. geophysical surveys).

b: Underwater noise from vessels and other vessel activities - given the large distances of all transboundary sites from the Proposed Development (closest site is located 292 km from the array area) and that the majority of vessel movements across all phases of the Proposed Development will likely be to/from ports on the east coast of Scotland, it is considered that vessel traffic will not result in a significant disturbance to Annex II harbour porpoise feature of any transboundary site. It is therefore concluded that there is no potential for LSE from vessel noise across all phases of the Proposed Development.

c: Vessel collision risk - the uplift in vessel traffic across all phases of the Proposed Development is considered to be low compared to current background levels and the likelihood of collisions occurring between vessels and marine mammals is considered to be low. Furthermore, the minimum distance between the Proposed Development and the nearest transboundary site is 292 km. There is therefore considered to be little potential for increased vessel activity to result in a significant effect in terms of collision risk and so it is concluded that there is no potential for LSE to the harbour porpoise feature of any transboundary site from vessel collision risk across all phases of the Proposed Development.

d: Changes in prey availability – any impacts to the fish community during the construction phase are anticipated to be highly localised, of short-term duration and temporary in nature. Impacts during the operation and maintenance and decommissioning phases are expected to be substantially less than during construction (as no piling will be required during the operation and maintenance phase). In addition, given the distance of the Proposed Development from the nearest transboundary site (292 km from the Proposed Development array area) and the large foraging range of this species, significant impacts to the foraging ability of harbour porpoise are considered unlikely. It is therefore concluded that there is no potential for LSE to the harbour porpoise feature of any transboundary site as a result of changes to prey availability across all phases of the Proposed Development.

e: Changes in water clarity – given the large distance between the Proposed Development and the transboundary sites for harbour porpoise (closest site is 292 km from the Proposed Development array area) and the fact that increases in SSC will be localised, short-term and intermittent, they are considered unlikely to result in significant effects to the foraging ability of harbour porpoise. It is considered that there is no potential for LSE on the Annex II harbour porpoise feature of any transboundary site from changes in water clarity.

f: Operational noise – noise levels from operational wind turbines are predicted to be low and the spatial extent of any potential behavioural impact to harbour porpoise will be small. Given the large distance between the Proposed Development and the transboundary sites for harbour porpoise (closest site is 292 km from the Proposed Development array area) and that several published studies indicate that harbour porpoise are not likely to be displaced from the operational wind farm, there is considered to be no potential for LSE as a result of wind turbine noise during the operation and maintenance phase.

h: Accidental pollution - a good practice approach will be implemented as part of the Proposed Development via post-consent plans (e.g. a PEMMP) to reduce potential impacts associated with accidental pollution events across all phases of the Proposed Development irrespective of the possible effects on European sites. Following advice from NS (2021) and MSS (2021), accidental pollution associated with construction activities is not considered as an effect pathway because this will be subject to other regulatory control through both legislation and the requirements for contingency plans. This rationale is taken to apply to all phases of the Proposed Development and the potential for LSE is discounted.

f: In-combination effects – over the distances considered, all relevant effect-pathways are considered extremely weak, such that only a negligible (if even detectable) influence would be apparent. Such effects could not contribute to any material degree to an in-combination effect and as such, in-combination effects associated with planned projects or other activities in the vicinity of the Proposed Development are also not anticipated for the harbour porpoise feature of any transboundary site.

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