Project alone: population-level impacts
  1. As determined above, the effect from the Proposed Development alone which could lead to an adverse effect on the Coquet Island SPA lesser black-backed gull population is collision mortality during the operation and maintenance phase. PVA was therefore undertaken. The approach and methods to undertaking the PVA are as described in the section on Project Alone: Population-Level Impacts for Forth Islands SPA lesser black-backed gull population above and in volume 3, appendix 11.6 of the Offshore EIA Report. The starting population size was the 2019 count for the SPA (Offshore EIA Report, volume 3, appendix 11.5).

 

Table 5.207:
Projected 35 Year Population Sizes and Associated PVA Metrics for the Coquet Island SPA Lesser Black-Backed Gull Population Under Different Impact Scenarios for the Proposed Development Alone.

Table 5.207: Projected 35 Year Population Sizes and Associated PVA Metrics for the Coquet Island SPA Lesser Black-Backed Gull Population Under Different Impact Scenarios for the Proposed Development Alone.

 

  1. The predicted population-level impacts are negligible, irrespective of whether these are determined using the Developer or Scoping Approach. The Scoping Approach CPS value indicates that the collision mortality associated with the Proposed Development alone would not result in a reduction of approximately 0.5% in the size of the SPA population after 35 years, relative to that in the absence of any wind farm effects ( Table 5.207   Open ▸ ). The associated reduction in annual population growth rate (relative to that predicted under baseline conditions) is estimated to be zero, whilst the centile value of 49.5 indicates significant overlap in the distributions of the predicted impacted and unimpacted population sizes and, hence, a high likelihood of the impacted population being of a similar size to the unimpacted population after 35 years. The metrics for the Developer Approach suggest even smaller levels of impact ( Table 5.207   Open ▸ ).
Project alone: conclusion
  1. For both the Developer and Scoping Approach, the potential effects from the Proposed Development alone on the Coquet Island SPA lesser black-backed gull population are predicted to be negligible, with the resultant population-level impacts also predicted to be negligible. The PVA metrics indicate a very high chance of the population being of a similar size to that which would occur in the absence of the Proposed Development after 35 years. Given this, it is concluded that the effects from the Proposed Development alone would not result in an adverse effect on this SPA population.
Effects in-combination
Effects of relevance to the in-combination assessment
  1. For the same reasons as described in Effects In-Combination for the Forth Islands SPA lesser black-backed gull population, the potential for effects of the Proposed Development to act on the Coquet Island SPA lesser black-backed gull population in-combination with other plans and projects is limited to collision risk during operation and maintenance. For the Coquet Island SPA lesser black-backed gull population, potential effects of collision are limited to the breeding season.
Collision risk - operation and maintenance
  1. Existing assessments for all UK North Sea and Channel offshore wind farms in operation, construction, consented or planning  were checked to determine the collision estimates to be attributed to the Coquet Island SPA lesser black-backed gull population (Offshore EIA Report, volume 3, appendix 11.6, annex E).
  2. Following the approach to estimating in-combination mortalities as outlined in volume 3, appendix 11.6, annex E of the Offshore EIA Report, there are no projects considered to have effects on the Coquet Islands SPA lesser black-backed gull population during the breeding season. Therefore, it is assumed that existing in-combination effects are inconsequential to this feature and that, in line with conclusions for the project alone, in-combination population-level impacts resulting from predicted collision mortality are negligible.
In-combination: conclusion
  1. On the basis of the above considerations, it is concluded that the population-level impacts resulting from the Proposed Development in-combination with the other UK North Sea wind farms would not produce an adverse effect on the Coquet Island SPA lesser black-backed gull population. This conclusion applies irrespective of whether effects are determined according to the Scoping Approach or the Developer Approach.

Assessment for the puffin population

  1. The Coquet Island SPA puffin population is currently estimated to number 25,029 breeding pairs (Offshore EIA Report, volume 3, appendix 11.5) based on the most recent count in 2019. Puffin are listed on the Coquet SPA citation as a named component of the breeding seabird assemblage, with a citation population size of 31,636 individuals, thus the numbers currently breeding on Coquet Island show an increase in the population since designation.
  2. Potential impacts on the Coquet Island SPA puffin population screened in for assessment are outlined in section 3 and in the HRA Stage One Screening Report (SSER, 2021b).

The potential for impacts on the puffin population

  1. The breeding period for puffin is defined as April to mid-August, following the NatureScot (2020) guidance. From published information on puffin foraging ranges generally (Woodward et al. 2019) it is possible that during the breeding period puffin from Coquet Island SPA occur within the Proposed Development and 2 km buffer. This is supported by the findings of the apportioning exercise, which estimates that 11% of the puffin occurring on the Proposed Development array area during the breeding season derive from this SPA colony (Offshore EIA Report, volume 3, appendix 11.5).
  2. As advised in the NatureScot scoping advice (volume 3, appendix 6.2 of the Offshore EIA Report), no assessment of impacts during the non-breeding period is undertaken for puffin.
Project alone: construction and decommissioning
Disturbance
  1. As outlined in the section on Project Alone: Construction and Decommissioning – Disturbance for the Forth Island SPA puffin population, direct disturbance to puffins during the assumed eight-year construction phase may arise within the Proposed Development as a result of increased vessel movements, as well as from other activities associated with the installation of the wind turbine foundations, cables and other infrastructure (see section 4.5; Table 4.1   Open ▸ ).
  2. The potential for disturbance effects during decommissioning is assumed to be the same (or less) as for construction, noting that the duration of the decommissioning phase will not exceed that of construction, and may be shorter.
  3. Given the relatively low sensitivity of puffin to disturbance effects (Garthe and Hüppop 2004; Furness et al., 2013), the relatively small areas that will be subject to activities with the potential to result in disturbance at any given time during the construction period and the fact that these potential effects will be temporary, it is considered that there is no potential for construction or decommissioning related disturbance to lead to an adverse effect on the Coquet Island SPA puffin population.
Displacement
  1. As detailed above, puffin is considered to have a low sensitivity to disturbance (Garthe and Hüppop 2004; Furness et al., 2013), and potential effects of disturbance during the construction and decommissioning phases will only extend across a very small part of the wider foraging areas used by the Coquet Island SPA puffin population during the breeding season. Furthermore, as detailed above, potential effects of disturbance will not occur simultaneously across the entirety of the Proposed Development array area and Proposed Development export cable corridor but will instead be carried out in different areas at different times. Thus, at any given time the potential for disturbance effects that could lead to displacement of puffin from this SPA during the breeding period will be limited to relatively small areas, with the potential effects also being of a temporary nature.
  2. Therefore, it is considered that there is no potential for construction or decommissioning related displacement to lead to an adverse effect on the Coquet Island SPA puffin population.
Changes to prey availability
  1. During construction and decommissioning there are a number of ways in which effects on key prey species of seabirds may occur, which are outlined in the section on Project Alone: Construction and Decommissioning – Changes to prey availability for the Forth Islands SPA puffin population. The same evidence basis and context applies to the Coquet Island SPA puffin population as to the Forth Islands SPA population in relation to the potential for such effects to lead to impacts on the population.
  2. Given this, it is considered that there is relatively little potential for the Coquet Island SPA puffin population to be affected by changes to prey availability during the construction and decommissioning phases, with any such effects being largely intermittent across a relatively small spatial extent, with most effects temporary in nature. Consequently, it is considered that there is no potential for construction or decommissioning related changes in prey availability to lead to an adverse effect on the Coquet Island SPA puffin population.
Project alone: operation and maintenance
Disturbance
  1. Vessel use and associated activities within the Proposed Development array area and export cable corridor during the operation and maintenance phase may lead to direct disturbance of puffins from Coquet Island SPA during the breeding periods, as outlined in the section on Project Alone: Operation and Maintenance – Disturbance for the Forth Islands SPA puffin population. The same evidence base and context applies to the Coquet Island SPA puffin population as to the Forth Islands SPA population in relation to the potential for such effects to lead to impacts on the population during the non-breeding periods.
  2. Given the discrete areas relative to the species’ breeding season foraging range that will be subject intermittently to potential disturbance from vessel use and maintenance activities, and the fact that these potential effects will be reduced compared to the construction and decommissioning phases, it is considered that there is no potential for disturbance during operation and maintenance to lead to an adverse effect on the Coquet Island SPA puffin population.
Displacement/Barrier effects
  1. The approach used to derive predicted levels of mortality for Coquet Island SPA puffins is as described in the section on Project Alone: Operation and Maintenance – Displacement/Barrier effects for the Forth Islands SPA puffin population (and in the Offshore EIA Report, volume 3, appendix 11.4)
  2. Estimates of puffin mortality for Coquet Island SPA were produced using the SNCB matrix on the basis of both the Scoping Approaches and the Developer Approach (Offshore EIA Report volume 3, appendix 11.4), with these estimates then apportioned to the Coquet Island SPA puffin population as described in the Offshore EIA Report, volume 3, appendix 11.5 and in the section on Project Alone: Operation and Maintenance – Displacement/Barrier Effects for the Forth Islands SPA puffin population (Table 5.208).

 

Table 5.208:
The Mean Peak Abundance Estimates of Puffin in the Proposed Development Array Area and 2 km Buffer for Each Seasonal Period, Together with the Proportion of Birds Estimated to Belong to the Breeding Adult Age Class and to be From the Coquet Island SPA Population in Each period. The Proportion of Adults Assumed to be Sabbaticals During the Breeding Season is Also Presented

Table 5.208: The Mean Peak Abundance Estimates of Puffin in the Proposed Development Array Area and 2 km Buffer for Each Seasonal Period, Together with the Proportion of Birds Estimated to Belong to the Breeding Adult Age Class and to be From the Coquet Island SPA Population in Each period. The Proportion of Adults Assumed to be Sabbaticals During the Breeding Season is Also Presented

 

  1. The potential annual mortality as a result of displacement is estimated as 3.6 adults and 4.9 immatures based on Scoping Approach A and as 6.0 adults and 8.1 immatures based Scoping Approach B ( Table 5.209   Open ▸ ). All mortality was attributable to the non-breeding periods. For the Developer Approach, annual displacement mortality was estimated as 1.0 adult and 1.4 immatures ( Table 5.209   Open ▸ ).
Table 5.209:
Estimated Potential Annual Mortality of Coquet Island SPA Puffins as a Result of Displacement from the Proposed Development Array Area and 2 km Buffer as Determined by the Scoping Approach and Developer Approach.

Table 5.209: Estimated Potential Annual Mortality of Coquet Island SPA Puffins as a Result of Displacement from the Proposed Development Array Area and 2 km Buffer as Determined by the Scoping Approach and Developer Approach.

 

  1. The additional annual mortality of adult puffins from the Coquet Island SPA population predicted due to displacement from the Proposed Development array area represents 0.007% of the current adult breeding population at this colony (i.e. 50,058 individuals – Table 3.3 in volume 3, appendix 11.5 of the Offshore EIA Report) as determined by Scoping Approach A, 0.012% as determined by Scoping Approach B, and 0.002% as determined by the Developer Approach. In terms of percentage increases in the baseline annual adult mortality of the population (which is based on applying a mortality rate of 0.099 – see Table 2.13 of volume 3, appendix 11.6 of the Offshore EIA Report), the estimates of adult mortality equate to an increase of 0.02% for the Developer Approach and of 0.07 – 0.12% for the lower and upper estimates from the Scoping Approach.
  2. Further consideration of the potential population-level impacts associated with the predicted displacement/barrier effect mortalities in Table 5.209   Open ▸ is undertaken below in the Project Alone: Population-Level Impacts section.
Changes to prey availability
  1. During the operation and maintenance phase there are a number of ways in which effects on key prey species may occur, which are outlined in the section on Project Alone: Construction and Decommissioning – Changes to prey availability for the Forth Islands SPA puffin population. The same evidence base and context applies to the Coquet Island SPA puffin population as to the Forth Islands SPA population in relation to the potential for such effects to lead to impacts on the population.
  2. Given this, it is considered that there is relatively little potential for the Coquet Island SPA puffin population to be affected by changes to prey availability during the operation and maintenance phase, with any such effects being largely intermittent across a relatively small spatial extent. Consequently, it is considered that there is no potential for operation or maintenance related changes in prey availability to lead to an adverse effect on the Coquet Island SPA puffin population.
Project alone: population-level impacts
  1. As determined above, the effects from the Proposed Development alone which could lead to an adverse effect on the Forth Islands SPA puffin population are limited to displacement (inclusive of barrier effects) during the operation and maintenance phase. For other effect pathways, there is considered to be no potential for an adverse effect on this population as a result of the Proposed Development alone, with any such effects likely to be small and of little, or no, consequence in terms of impacts at the population level.
  2. As described in volume 3, appendix 11.6 of the Offshore EIA Report, PVAs were run for populations where the predicted wind farm associated mortality increased the baseline mortality rate by at least 0.02 percentage point (Offshore EIA Report, volume 3, appendix 11.8). Predicted displacement mortality for the Coquet Island SPA puffin population did not exceed this threshold under any approach and as such, PVA was not undertaken. Accordingly, it is considered that there is no potential for operation or maintenance related displacement/barrier effects to lead to an adverse effect on the Coquet Island SPA puffin population.
Project alone: Conclusion
  1. For both the Developer and Scoping Approaches, the potential effects from the Proposed Development alone on the Coquet Island SPA puffin population are predicted to be very small, with the resultant population-level impacts also predicted to be very small. Given this, it is concluded that the effects from the Proposed Development alone would not result in an adverse effect on this SPA population.
Effects in-combination
Effects of relevance to the in-combination assessment
  1. For the same reasons as described in Effects in-combination for the Forth Islands SPA puffin population, the potential for effects of the Proposed Development to act on the Coquet Island SPA puffin population in-combination with other plans and projects is limited to displacement (inclusive of barrier effects) during operation and maintenance. For the Coquet Island SPA puffin population, potential effects of displacement are limited to the breeding season.
Displacement/Barrier effects – operation and maintenance
  1. Existing assessments for all UK North Sea and Channel offshore wind farms in operation, construction, consented or planning were checked to determine the displacement mortality estimates to be attributed to the Coquet Island SPA puffin population (Offshore EIA Report, volume 3, appendix 11.6, annex E).
  2. Following the approach to estimating in-combination mortalities as outlined in volume 3, appendix 11.6, annex E of the Offshore EIA Report, there are no projects considered to have effects on the Coquet Islands SPA puffin population during the breeding season. Therefore, it is assumed that existing in-combination effects are inconsequential to this feature and that, in line with conclusions for the project alone, in-combination population-level impacts resulting from predicted collision mortality are negligible.
In-combination: Conclusion
  1. On the basis of the above considerations, it is concluded that the population-level impacts resulting from the Proposed Development in-combination with the other UK North Sea wind farms would not produce an adverse effect on the Coquet Island SPA puffin population. This conclusion applies irrespective of whether effects are determined according to the Scoping Approach or the Developer Approach.

Assessment for the breeding seabird assemblage

  1. The breeding seabird assemblage for the Coquet Island SPA is a qualifying feature on the basis of the SPA supporting in excess of 20,000 individual seabirds (with the citation noting a total of 47,662 individual breeding seabirds based on the five year mean peak of 2010-2014). Roseate tern, common tern, Sandwich tern, Arctic tern, puffin, black-headed gull, fulmar, herring gull, lesser black-backed gull and kittiwake are amongst the species identified in the citation as having nationally important populations which contribute to the Coquet Island SPA breeding seabird assemblage.
  2. Potential impacts of the Proposed Development alone and in-combination with either the other Forth and Tay or the other UK North Sea wind farms on the breeding seabird assemblage for the SPA could arise via effects on the named components of the assemblage feature. For both the Scoping Approach and the Developer Approach, the assessments undertaken above identify no potential for adverse effects on kittiwakes, lesser black-backed gulls or puffins for the project along or in-combination with other plans or projects. Likely significant effects on all other named components of the assemblage have been screened out (Table 5.198). 
  3. Therefore, it is concluded that there is no potential for an adverse effect on the Coquet Islands SPA breeding seabird assemblage. This conclusion applies to the assessments undertaken according to both the Developer Approach and the Scoping Approach.

 

Site conclusion
  1. It is concluded that there is no potential for an Adverse Effect on Integrity on the Coquet Island SPA from the Proposed Development alone or in-combination with other UK North Sea wind farms. This conclusion applies to the assessments undertaken according to both the Developer Approach and the Scoping Approach.

5.7.10.              North Caithness Cliffs SPA

European site information and conservation objectives

  1. North Caithness Cliffs SPA includes sea-cliff areas between Freswick Bay and Strathy Point on the north coast of the Scottish mainland, in addition to the island of Stroma. The site is located approximately 280 km from the Proposed Development. The boundary of the SPA overlaps either partly or wholly with Duncansby Head Site of SSSI, Stroma SSSI, Dunnet Head SSSI, Holborn Head SSSI, and Red Point Coast SSSI. The seaward extension extends approximately 2 km into the marine environment. The SPA was classified in 1996, with the marine extension classified in 2009.
  2. The site qualifies under Article 4.2 by regularly supporting one migratory seabird species and in excess of 20,000 breeding seabird. The assemblage comprises five named component species ( Table 5.210   Open ▸ ). The potential for LSE has been identified in relation to two of these five species: kittiwake and puffin ( Table 5.210   Open ▸ ), with the effect pathways associated with LSE for each of these detailed in Table 3.1   Open ▸ and set out in the assessment below.
  3. The conservation objectives of this SPA (as determined from NatureScot’s SiteLink (NatureScot 2022) are:
  • To avoid deterioration of the habitats of the qualifying species (listed below) or significant disturbance to the qualifying species, thus ensuring that the integrity of the site is maintained; and
  • To ensure for the qualifying species that the following are maintained in the long term:

–      Population of the species as a viable component of the site;

–      Distribution of the species within site;

–      Distribution and extent of habitats supporting the species;

–      Structure, function and supporting processes of habitats supporting the species; and

–      No significant disturbance of the species.

  1. The Proposed Development does not overlap with the SPA, so that potential impacts on its qualifying features will only occur as a result of individuals from the colony occurring in the area (or vicinity) of the Proposed Development.
  2. Consequently, the focus of the assessment for this SPA population is concerned with the conservation objective to maintain or restore the populations of each qualifying feature because the other conservation objectives either apply to the site itself, and not to areas beyond the boundary, or are encompassed by the assessment of this conservation objective.
  3. Further information on this European site is presented in appendix 3A.

 

Table 5.210:
Details on the Qualifying Features of the North Caithness Cliffs SPA

Table 5.210: Details on the Qualifying Features of the North Caithness Cliffs SPA

*Named components of the assemblage only.

 

Assessment for the kittiwake population

  1. The North Caithness Cliffs SPA kittiwake population is currently estimated to number 13,100 breeding pairs (Offshore EIA Report, volume 3, appendix 11.5) based on the most recent count in 2021. Kittiwake are listed on the North Caithness Cliffs SPA citation as a named component of the breeding seabird assemblage.
  2. Potential impacts on the North Caithness Cliffs SPA kittiwake population screened in for assessment are outlined in section 3 and in the HRA Stage One Screening Report (SSER, 2021b).
The potential for impacts on the kittiwake population
  1. The breeding period for kittiwake is defined as mid-April to August, following the NatureScot (2020) guidance. From published information on kittiwake foraging ranges generally (Woodward et al., 2019) it is apparent that during the breeding period kittiwakes from North Caithness Cliffs SPA could occur in the vicinity of the Proposed Development. However, the findings of the apportioning exercise found that no kittiwakes occurring in the Proposed Development array area during the breeding season derived from this SPA (Offshore EIA Report, volume 3, appendix 11.5).
  2. In the non-breeding season kittiwakes are largely pelagic (Frederiksen et al., 2011), although most of those which breed on the North Sea coast likely winter in the North Sea and Celtic Sea. Therefore, it is likely that there is the potential for birds from the North Caithness Cliffs SPA population to pass through offshore wind farms in the North Sea during the autumn and spring passage periods (defined as September to December and January to mid-April, respectively - Furness 2015; NatureScot 2020; volume 3, appendix 11.5 of the Offshore EIA Report). Given the above, the Proposed Development may have potential effects on the North Caithness Cliffs SPA kittiwake population during the non-breeding passage periods only (Offshore EIA Report, volume 3, appendix 11.5).
Project alone: construction and decommissioning
Disturbance
  1. Direct disturbance to kittiwakes during the assumed eight-year construction phase may arise within the Proposed Development as a result of increased vessel movements, as well as from other activities associated with the installation of the wind turbine foundations, cables and other infrastructure (see the section on Project Alone: Construction and Decommissioning – Disturbance for St. Abb’s Head to Fast Castle kittiwake population ( Table 4.1   Open ▸ ).
  2. The potential for disturbance effects during decommissioning is assumed to be the same (or less) as for construction, noting that the duration of the decommissioning phase will not exceed that of construction, and may be shorter.
  3. Kittiwakes breeding at the North Caithness Cliffs SPA are not predicted to utilise the Proposed Development during the breeding season (Offshore EIA Report, volume 3, appendix 11.5). During the non-breeding periods, kittiwake distribution is not constrained by the location of the breeding colonies and birds from the SPA population are likely to occur across large expanses of oceanic and maritime waters (Frederiksen et al., 2012, Furness 2015). The potential for effects of construction- and decommissioning-related disturbance is therefore low.
  4. Furthermore, given the low sensitivity of kittiwake to disturbance effects (Garthe and Hüppop 2004; Furness et al., 2013), and the relatively small areas that will be subject to activities with the potential to result in intermittent, temporary disturbance (see the section on Project Alone: Construction and Decommissioning – Disturbance for St. Abb’s Head to Fast Castle kittiwake population), it is considered that there is no potential for construction or decommissioning related disturbance to lead to an adverse effect on the North Caithness Cliffs SPA kittiwake population. This conclusion is consistent with the outcome of the EIA which ‘screened’ out kittiwake as a species for which detailed consideration of the effects of construction disturbance was required (Offshore EIA Report, volume 2, chapter 11).
Displacement
  1. As detailed above, kittiwake is considered to have a low sensitivity to disturbance (Garthe and Hüppop 2004; Furness et al., 2013), and potential effects of disturbance during the construction and decommissioning phases will only extend across a very small part of the wider foraging areas used by the North Caithness Cliffs SPA kittiwake population during the non-breeding season. Furthermore, as detailed in see the section on Project Alone: Construction and Decommissioning – Displacement for St. Abb’s Head to Fast Castle SPA kittiwake population, potential effects of disturbance will not occur simultaneously across the entirety of the Proposed Development array area and Proposed Development export cable corridor but will instead be carried out in different areas at different times. Thus, at any given time the potential for disturbance effects that could lead to displacement of kittiwake from this SPA during the non-breeding periods will be limited to relatively small areas, with the potential effects also being of a temporary nature.
  2. Therefore, it is considered that there is no potential for construction or decommissioning related displacement to lead to an adverse effect on the North Caithness Cliffs SPA kittiwake population.
Changes to prey availability
  1. During construction and decommissioning there are a number of ways in which effects on key prey species of seabirds may occur, which are outlined in the section on Project Alone: Construction and Decommissioning – Changes to prey availability for the St Abb’s Head to Fast Castle SPA kittiwake population. The same evidence basis and context applies to the North Caithness Cliffs SPA kittiwake population as to the St Abb’s Head to Fast Castle SPA population in relation to the potential for such effects to lead to impacts on the population.
  2. Given this, it is considered that there is relatively little potential for the North Caithness Cliffs SPA kittiwake population to be affected by changes to prey availability during the construction and decommissioning phases, with any such effects being largely intermittent across a relatively small spatial extent, with most effects temporary in nature. Consequently, it is considered that there is no potential for construction or decommissioning related changes in prey availability to lead to an adverse effect on the North Caithness Cliffs SPA kittiwake population.
Project alone: operation and maintenance
Disturbance
  1. Vessel use and associated activities within the Proposed Development array area and export cable corridor during the operation and maintenance phase may lead to direct disturbance of kittiwakes from the North Caithness Cliffs SPA during the non-breeding periods, as outlined in the section on Project Alone: Operation and Maintenance – Disturbance for the St. Abb’s Head to Fast Castle SPA kittiwake population. The same evidence base and context applies to the North Caithness Cliffs SPA kittiwake population as to the St Abb’s Head to Fast Castle SPA population in relation to the potential for such effects to lead to impacts on the population during the non-breeding periods.
  2. Given the discrete areas relative to the species’ non-breeding season foraging range that will be subject intermittently to potential disturbance from vessel use and maintenance activities, and the fact that these potential effects will be reduced compared to the construction and decommissioning phases, it is considered that there is no potential for disturbance during operation and maintenance to lead to an adverse effect on the North Caithness Cliffs SPA kittiwake population.
Displacement/Barrier effects
  1. The approach used to derive predicted levels of mortality for North Caithness Cliffs SPA kittiwakes is as described in the section on Project Alone: Operation and Maintenance – Displacement/Barrier effects  for the St Abb’s Head to Fast Castle SPA kittiwake population (and in Offshore EIA Report, volume 3, appendix 11.4)
  2. Estimates of kittiwake mortality for North Caithness Cliffs SPA were produced using the SNCB matrix on the basis of both the Scoping Approaches and the Developer Approach (Offshore EIA Report, volume 3, appendix 11.4), with these estimates then apportioned to the North Caithness Cliffs SPA kittiwake population as described in volume 3, appendix 11.5 of the Offshore EIA Report and in the section on Project Alone: Operation and Maintenance – Displacement/Barrier effects  for the St Abb’s Head to Fast Castle SPA kittiwake population (and according to the apportioning estimates in Table 5.211).

 

Table 5.211:
The Mean Peak Abundance Estimates of Kittiwake in the Proposed Development Array Area and 2 km Buffer for Each Seasonal Period, Together with the Proportion of Birds Estimated to Belong to the Breeding Adult Age Class and to be from the North Caithness Cliffs SPA Population in Each Period. The Proportion of Adults Assumed to be Sabbaticals During the Breeding Season is also Presented.

Table 5.211: The Mean Peak Abundance Estimates of Kittiwake in the Proposed Development Array Area and 2 km Buffer for Each Seasonal Period, Together with the Proportion of Birds Estimated to Belong to the Breeding Adult Age Class and to be from the North Caithness Cliffs SPA Population in Each Period. The Proportion of Adults Assumed to be Sabbaticals During the Breeding Season is also Presented.

 

Table 5.212:
Estimated Potential Annual Mortality of North Caithness Cliffs SPA Kittiwakes as a Result of Displacement from the Proposed Development Array Area and 2 km Buffer as Determined by the Scoping Approach and Developer Approach.

Table 5.212: Estimated Potential Annual Mortality of North Caithness Cliffs SPA Kittiwakes as a Result of Displacement from the Proposed Development Array Area and 2 km Buffer as Determined by the Scoping Approach and Developer Approach.

 

  1. The potential annual mortality as a result of displacement is estimated as 1.3 adult and 0.7 immature birds based on Scoping Approach A and as 3.9 adult and 1.9 immature birds based Scoping Approach B ( Table 5.212   Open ▸ ) All mortality was attributable to the non-breeding periods.
  2. The potential annual mortality as a result of displacement is estimated as 1.3 adult and 0.7 immature birds based on Scoping Approach A and as 3.9 adult and 1.9 immature birds based Scoping Approach B ( Table 5.212   Open ▸ ) All mortality was attributable to the non-breeding periods.
  3. No mortality from displacement was predicted using the Developer Approach for any age class or season.
  4. The additional annual mortality of adult kittiwakes from the North Caithness Cliffs SPA population predicted due to displacement from the Proposed Development array area represents 0.02% of the current adult breeding population at this colony (i.e. 7,712 individuals – Table 3.3 in volume 3, appendix 11.5 of the Offshore EIA Report) as determined by Scoping Approach A, and 0.05% as determined by Scoping Approach B. In terms of percentage increases in the baseline annual adult mortality of the population (which is based on applying a mortality rate of 0.146 – see Table 2.13 of volume 3, appendix 11.6 of the Offshore EIA Report), the estimates of adult mortality equate to an increase of 0.11 – 0.34% for the lower and upper estimates from the Scoping Approach. As outlined above and in ( Table 5.212   Open ▸ ) no mortality was predicted using the Developer Approach.
  5. The potential levels of impact on the North Caithness Cliffs SPA kittiwake population resulting from predicted displacement/barrier effects associated with the Proposed Development array area during the operation and maintenance phase are considered further below in the Project Alone: Population-Level Impacts section. This presents the outputs from PVAs of the combined effects of predicted displacement and collision mortality on the SPA population.
Collision risk
  1. The approach used to derive predicted levels of mortality for North Caithness Cliffs SPA kittiwakes is as described in the section on Project Alone: Operation and Maintenance – Collision risk for the St Abb’s Head to Fast Castle SPA kittiwake population (and in Offshore EIA Report volume 3, appendix 11.3)
  2. Based upon option 2 of the deterministic CRM with a 98.9% avoidance rate applied, the annual collision mortality of kittiwakes from the North Caithness Cliffs SPA is predicted to be approximately 6.3 adults and 3.3 immatures as determined by the Scoping Approach, and approximately 4.5 adults and 2.3 immatures as determined by the Developer Approach ( Table 5.213   Open ▸ ). All mortality was attributable to the non-breeding periods.

 

Table 5.213:
Predicted Collision Effects from the Proposed Development on the North Caithness Cliffs SPA Kittiwake Population, as Determined by the Scoping Approach and Developer Approach. Estimates are for the Maximum Design Scenario and are Based on Option 2 of the Deterministic CRM Using a 98.9% Avoidance Rate.

Table 5.213: Predicted Collision Effects from the Proposed Development on the North Caithness Cliffs SPA Kittiwake Population, as Determined by the Scoping Approach and Developer Approach. Estimates are for the Maximum Design Scenario and are Based on Option 2 of the Deterministic CRM Using a 98.9% Avoidance Rate.

 

  1. The additional annual mortality of adult kittiwakes from the North Caithness Cliffs SPA population predicted due to collision represents approximately 0.06% of the number of adults currently estimated to breed at this colony (i.e. 7,712 individuals – Table 3.3 in volume 3, appendix 11.5 of the Offshore EIA Report) as determined by the Developer Approach and approximately 0.08% as determined by the Scoping Approach. In terms of percentage increases in the baseline annual adult mortality of the population (which is based on applying a mortality rate of 0.146 – see Table 2.13 of volume 3, appendix 11.6 of the Offshore EIA Report), the predicted adult collision mortality equates to increases of 0.40% and 0.56% for the Developer and Scoping Approaches, respectively.
  2. As outlined in the Project Alone: Operation and Maintenance - Collision risk section for the St Abb’s Head to Fast Castle SPA kittiwake population, using the collision estimates derived from the site-specific flight height data or from the stochastic CRM with avoidance rates as calculated for the bird collision-avoidance study (Bowgen and Cook 2018) would result in predicted collision mortalities on the North Caithness Cliffs SPA kittiwake population that are at least 50% lower than those presented in Table 5.213   Open ▸ above (and on which the assessment is based).
  3. The potential levels of impact on the North Caithness Coast SPA kittiwake population resulting from predicted collision mortality associated with the Proposed Development array area during the operation and maintenance phase are considered further below in the Project Alone: Population-Level Impacts section. This presents the outputs from PVAs of the combined effects of predicted displacement and collision mortality on the SPA population.
Changes to prey availability
  1. During the operation and maintenance phase there are a number of ways in which effects on key prey species may occur, which are outlined in the section on Project Alone: Construction and Decommissioning – Changes to prey availability for the St Abb’s Head to Fast Castle SPA kittiwake population. The same evidence base and context applies to the North Caithness Cliffs SPA kittiwake population as to the St Abb’s Head to Fast Castle SPA population in relation to the potential for such effects to lead to impacts on the population.
  2. Given this, it is considered that there is relatively little potential for the North Caithness Cliffs SPA kittiwake population to be affected by changes to prey availability during the operation and maintenance phase, with any such effects being largely intermittent across a relatively small spatial extent. Consequently, it is considered that there is no potential for operation or maintenance related changes in prey availability to lead to an adverse effect on the North Caithness Cliffs SPA kittiwake population.
Project alone: population-level impacts
  1. As determined above, the effects from the Proposed Development alone which could lead to an adverse effect on the North Caithness Cliffs SPA kittiwake population are displacement (inclusive of barrier effects) and collision mortality during the operation and maintenance phase.
  2. PVA was therefore undertaken on the mortality to the adult and immature age classes predicted due to the combined displacement and collision effects associated with the Proposed Development, as determined by both the Scoping and Developer Approaches (see Table 5.212   Open ▸ and Table 5.213   Open ▸ ).   The approach and methods to undertaking the PVA are as described in the section on Project Alone: population-level impacts for St Abb’s Head to Fast Castle SPA kittiwake population above and in volume 3, appendix 11.6 of the Offshore EIA Report. The starting population size was the 2021 count for the SPA (Offshore EIA Report, volume 3, appendix 11.5).

 

Table 5.214:
Projected 35 Year Population Sizes and Associated PVA Metrics for the North Caithness Cliffs SPA Kittiwake Population under Different Impact Scenarios for the Proposed Development Alone.

Table 5.214: Projected 35 Year Population Sizes and Associated PVA Metrics for the North Caithness Cliffs SPA Kittiwake Population under Different Impact Scenarios for the Proposed Development Alone.

 

  1. The PVA predicted a continuing population decline for the North Caithness Cliffs SPA kittiwake population, irrespective of the effects from the Proposed Development. Thus, under baseline conditions (i.e. no wind farm effects), the population is predicted to decline by 36% after 35 years from the current estimate of 7,712 adult birds ( Table 5.214   Open ▸ ). Given that the PVAs are based on density independent models, which assume all mortality from the wind farm effects is additive and that there are no compensatory mechanisms operating within the population, the predicted declines are inevitably greater for those scenarios incorporating the effects from the Proposed Development.
  2. The PVA metrics suggest that the effects from the Proposed Development will lead to relatively small population-level impacts, with the CPS values indicating that the SPA population size would be reduced by approximately 2% and between 3.4 and 4.5%, relative to the predicted population size under baseline conditions, after 35 years for the Developer Approach and Scoping Approach, respectively ( Table 5.214   Open ▸ ). Reductions in the annual population growth rate (relative to that predicted under baseline conditions) are estimated to be 0.1% on the basis of both the Developer Approach and Scoping Approaches ( Table 5.214   Open ▸ ). On the basis of the Developer Approach, centile values are estimated to be 48.7 after 35 years, whilst for the Scoping Approach the equivalent values are between 46.7 and 47.3 ( Table 5.214   Open ▸ ). Thus, the centile metric indicates extensive overlap in the distribution of the predicted impacted and un-impacted population sizes, suggesting a low likelihood of the impacted population being smaller than the un-impacted population after 35 years, irrespective of whether the effects are estimated using the Developer or Scoping Approaches.
Project alone: Conclusion
  1. For both the Developer and Scoping Approaches, the potential effects from the Proposed Development alone on the North Caithness Cliffs SPA kittiwake population are predicted to be small, with the resultant population-level impacts also predicted to be small. The PVA metrics indicate a high chance of the population being of a similar size to that which would occur in the absence of the Proposed Development after 35 years. Given this, it is concluded that the effects from the Proposed Development alone would not result in an adverse effect on this SPA population.
Effects in-combination
Effects of relevance to the in-combination assessment
  1. For the same reason as described in the Effects in-combination for the St. Abb’s Head to Fast Castle SPA kittiwake population, the potential for effects of the Proposed Development to act on the North Caithness Cliffs SPA kittiwake population in-combination with other plans and projects is limited to displacement/barrier effect and collision risk pathways during operation and maintenance.
  2. In-combination totals have been collated for all relevant SPA populations for all UK North Sea and Channel offshore wind farms in operation, construction, consented or planning (Offshore EIA Report, volume 3, appendix 11.6, annex E). Separate in-combination totals for the Forth and Tay projects were not collated for the reasons outlined in Effects in-combination for the Farne Islands SPA kittiwake population, volume 3, appendix 11.6, annex E and volume 3, appendix 11.8 of the Offshore EIA Report.
Displacement/Barrier effects – operation and maintenance
  1. The approach and methods for estimating in-combination displacement mortality are described in Effects in-combination: Displacement/Barrier Effects – Operation and Maintenance for St Abb’s Head to Fast Castle SPA kittiwake population above and in volume 3, appendix 11.6, annex E of the Offshore EIA Report.

The potential mortality estimates derived for the other projects were combined with those for the Proposed Development to give in-combination estimates for the UK North Sea wind farm scenario, according to both the Scoping Approaches and Developer Approach ( Table 5.215   Open ▸ ).

 

Table 5.215:
Estimated Annual Mortality of North Caithness Cliffs SPA Kittiwakes as a Result of Displacement from the Proposed Development Array Area and 2 km Buffer as Determined by the Scoping Approach and Developer Approach, in-Combination with Other UK North Sea Wind Farms.

Table 5.215: Estimated Annual Mortality of North Caithness Cliffs SPA Kittiwakes as a Result of Displacement from the Proposed Development Array Area and 2 km Buffer as Determined by the Scoping Approach and Developer Approach, in-Combination with Other UK North Sea Wind Farms.

 

  1. For the Proposed Development in-combination with the other UK North Sea wind farms, the additional annual mortality of adult kittiwakes from the North Caithness Cliffs SPA population predicted due to displacement represents 0.02% of the current adult population as determined by the Developers Approach and between approximately 0.09-0.29% as determined by Scoping Approach A and B. In terms of percentage increases in the baseline annual adult mortality of the population, the estimates of adult displacement mortality equate to an increase of 0.18% for the Developers Approach and between 0.67 – 2.04% for the lower and upper estimates from the Scoping Approach.
  2. The potential levels of impact on the North Caithness Cliffs SPA kittiwake population resulting from predicted displacement/barrier effects associated with the Proposed Development array area in-combination with other UK North Sea wind farms during the operation and maintenance phase are considered further below in the In-combination: population-level impacts section. This presents the outputs from PVAs of the combined in-combination effects of predicted displacement and collision mortality on the SPA population.
Collision risk - operation and maintenance
  1. The approach and methods for estimating in-combination collision mortality are described in Effects in-combination: Collision – Operation and Maintenance for St Abb’s Head to Fast Castle SPA kittiwake population above and in volume 3, appendix 11.6, annex E of the Offshore EIA Report.
  2. The potential mortality estimates derived for the other projects were combined with those for the Proposed Development to give in-combination estimates for the UK North Sea wind farm scenario, according to both the Scoping Approach and Developer Approach ( Table 5.216   Open ▸ ).

 

Table 5.216:
Predicted Collision Effects on the North Caithness Cliffs SPA Kittiwake Population Due to the Proposed Development in-Combination with Other Projects in the UK North Sea Waters. Estimates are Presented for Both the Scoping Approach and Developer Approach for Consented Designs.

Table 5.216 Predicted Collision Effects on the North Caithness Cliffs SPA Kittiwake Population Due to the Proposed Development in-Combination with Other Projects in the UK North Sea Waters. Estimates are Presented for Both the Scoping Approach and Developer Approach for Consented Designs.

 

  1. For the Proposed Development in-combination with the other UK North Sea wind farms, the additional annual mortality of adult kittiwakes from the North Caithness Cliffs SPA population predicted due to collisions represents 0.49% of the current adult breeding population at this colony (i.e. 7,712 individuals – Table 3.3 in volume 3, appendix 11.5 of the Offshore EIA Report) as determined by the Developer Approach, and 0.51% of this population as determined by the Scoping Approach. In terms of percentage increases in the baseline annual adult mortality of the population, the estimates of adult collision mortality equate to an increase of 3.38% for the Developer Approach and of 3.51% for the Scoping Approach
  2. The potential levels of impact on the Coquet Island SPA kittiwake population resulting from predicted collision mortality associated with the Proposed Development array area in-combination with other UK North Sea wind farms during the operation and maintenance phase are considered further below in the In-combination: population-level impacts section. This presents the outputs from PVAs of the combined in-combination effects of predicted displacement and collision mortality on the SPA population.
In-combination: population-level impacts
  1. As for the Proposed Development alone, PVA was undertaken on the mortality to the adult and immature age classes predicted due to the combined displacement and collision effects associated with the Proposed Development in-combination with the other UK North Sea wind farms. This was on the basis of the potential mortality as determined by both the Scoping and Developer Approaches (see Table 5.215   Open ▸ and Table 5.216   Open ▸ above).
  2. The approach to the PVA and the metrics used to summarise the PVA outputs are as described for In-combination: population-level impacts for St Abb’s Head to Fast Castle SPA kittiwake population above and in the Offshore EIA Report, volume 3, appendix 11.6.

 

Table 5.217:
Projected 35 Year Population Sizes and Associated PVA Metrics for the North Caithness Cliffs SPA Kittiwake Population Under Different Impact Scenarios for the Proposed Development in-Combination with the Other UK North Sea Wind Farms.

Table 5.217: Projected 35 Year Population Sizes and Associated PVA Metrics for the North Caithness Cliffs SPA Kittiwake Population Under Different Impact Scenarios for the Proposed Development in-Combination with the Other UK North Sea Wind Farms.

 

  1. For the Developers Approach the CPS value indicates that the combined collision and displacement mortality associated with the Proposed Development alone would result in a reduction of approximately 14.5% in the size of the SPA population after 35 years, relative to that in the absence of any wind farm effects ( Table 5.217   Open ▸ ). The Scoping Approaches predict that the combined collision and displacement mortality associated with the Proposed Development alone would result in a reduction of between approximately 17.4% and 22.8% in the size of the SPA population after 35 years ( Table 5.217   Open ▸ ).
  2. The associated reduction in annual population growth rate (relative to that predicted under baseline conditions) is estimated to be between 0.4 and 0.7%, whilst the centile values of between 30.8 and 38.2  indicates a moderate level of overlap in the distributions of the predicted impacted and unimpacted population sizes and, hence the potential for the impacted population being of a similar size to the unimpacted population after 35 years. ( Table 5.217   Open ▸ ).