PVA Assessment Excluding Berwick Bank
  1. When considering the annual impact on the annual regional population, under the most extreme scenario (30% displacement and 3% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was 0.875 ( Table 11.44   Open ▸ ). The median population size was therefore projected to be 12.53% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 41.88. In terms of the population size, this means that the median of the impacted population fell within the 41st percentile of the unimpacted population (a value of 50 would indicate that they are the same). This suggests that the impacted scenario was still well within the margin of error of the non-impacted scenario, and therefore there would likely be no adverse effect to the population. However, as stated the CPGR is considered a more robust metric compared to the CPS in this analysis due to the models being conducted with density independence, in line with NatureScot (2023k) guidance. The PVA model predicted that the CPGR was 0.996 ( Table 11.44   Open ▸ ) which translates to a median reduction of 0.37% in population growth rate after 35 years. Such a decrease indicates that this level of impact would not adversely affect the population and would only result in a slight reduction in the growth rate currently seen in the BDMPS population and would therefore be undetectable against natural population fluctuations. Furthermore, it is not expected to significantly alter the background mortality rate.

 

Table 11.44:
Kittiwake 35 Year Cumulative PVA Results for Displacement Impacts Excluding Berwick Bank on an Annual Basis

Table 11.44 Kittiwake 35 Year Cumulative PVA Results for Displacement Impacts Excluding Berwick Bank on an Annual Basis

 

  1. Based on the PVA results using the 30% displacement and 3% mortality rate of the NatureScot Approach, the magnitude of impact on the kittiwake population annually is considered to be of low magnitude.
                        Magnitude of impact
  1. The estimated mortality resulting from displacement during operation and maintenance was assessed for each season, and also on an annual basis by combining seasonal impacts and comparing them against the largest regional seasonal population (as set out in volume 3, appendix 11.3, and summarised in Table 11.20   Open ▸ ).
  2. Based on the displacement assessment, for the pre-breeding and post-breeding season with Berwick Bank included and following the NatureScot Approach using a 30% displacement and 1% mortality rate, the cumulative impact was perceived as low magnitude.
  3. Based on the displacement assessment, for the pre-breeding and post-breeding season with Berwick Bank included and following the NatureScot Approach using a 30% displacement and 3% mortality rate, the cumulative impact was perceived as low magnitude.
  4. Based on the displacement assessment, for the pre-breeding and post-breeding season with Berwick Bank included and following the Applicant Approach using a 30% displacement and 1% mortality rate, the cumulative impact was perceived as low magnitude.
  5. Based on the PVA results for the breeding season with Berwick Bank included and following the NatureScot Approach using a 30% displacement and 3% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  6. Based on the displacement assessment, for the breeding season with Berwick Bank included and following the NatureScot Approach using a 30% displacement and 1% mortality rate, the cumulative impact was perceived as low magnitude.
  7. Based on the displacement assessment, for the breeding season with Berwick Bank included and following the Applicant Approach using a 30% displacement and 1% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  8. Based on the  PVA results, on an annual basis with Berwick Bank included and following the NatureScot Approach using a 30% displacement and 3% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  9. Based on the displacement assessment, on an annual basis with Berwick Bank included and following the NatureScot Approach using a 30% displacement and 1% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  10. Based on the displacement assessment, on an annual basis with Berwick Bank included and following the Applicant Approach using a 30% displacement and 1% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  11. Based on the displacement assessment, for the pre-breeding, breeding and post-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 30% displacement and 3% mortality rate, the cumulative impact was perceived as low magnitude.
  12. Based on the displacement assessment, for the pre-breeding, breeding and post-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 30% displacement and 1% mortality rate, the cumulative impact was perceived as low magnitude.
  13. Based on the displacement assessment, for the pre-breeding, breeding and post-breeding season with Berwick Bank excluded and following the Applicant Approach using a 30% displacement and 1% mortality rate, the cumulative impact was perceived as low magnitude.
  14. Based on the  PVA results, on an annual basis with Berwick Bank excluded and following the NatureScot Approach using a 30% displacement and 3% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  15. Based on the displacement assessment, on an annual basis with Berwick Bank excluded and following the NatureScot Approach using a 30% displacement and 1% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  16. Based on the displacement assessment, on an annual basis with Berwick Bank excluded and following the Applicant Approach using a 30% displacement and 1% mortality rate, the impact from the cumulative assessment was perceived as low magnitude.
  17. Kittiwake populations have been declining within the UK with Burnell et al. (2023) reporting that the population has decreased by 21%. However it is evident that this decline is attributed to the presence of other pressures such as poor prey resources which can impact productivity (Furness & Tasker, 2000; Frederiksen et al., 2008; Carroll et al., 2017) and challenges from climate change (Heath et al, 2012). The PVA indicated that cumulative mortality attributed to offshore wind farms would have a minimal impact on the overall population trajectory.
  18. The cumulative effect is predicted to be of national spatial extent, long-term duration, continuous and high reversibility. It is predicted that the impact will affect the receptor directly. The magnitude is therefore, considered to be low.
                        Sensitivity of the receptor
  1. In terms of behavioural response to offshore vessel traffic and helicopters, kittiwake are considered have a low vulnerability (Wade et al., 2016).
  2. Kittiwake is a qualifying interest for several SPAs likely to be connected to the Array (within the mean-max + SD foraging range), with several non-SPA colonies also within range and so the species is considered to be of international value. Refer to Table 6.2 of volume 3, appendix 11.1 for details of SPAs with connectivity to the Array with regards to kittiwake.
  3. Kittiwake lay two eggs and breed from the age of three onwards, typically living on average for 12 years (Burnell et al., 2023). Kittiwake have undergone decreases of approximately 57% in Scotland since the early 2000s. Surveys managed by the RSPB in 2023 have recorded indicative increases of 8% across a number of sites in Britain in 2023 when compared against a pre-HPAI baseline (Tremlett et al., 2024). Overall, kittiwake is deemed to have low recoverability.
  4. Kittiwake is deemed to be of low vulnerability, low recoverability and international value. The sensitivity of the receptor is therefore considered to be high.

                        Significance of the effect

  1. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of minor to moderate adverse significance. However, due to the pre-breeding season and post-breeding season falling below 1% and due to PVA results concluding there to be a low impact both with and without Berwick Bank and following both the NatureScot and Applicant’s Approach, it is considered that minor adverse significance is appropriate, which is not significant in EIA terms.
                        Guillemot
  1. The estimated abundance of guillemot for the purpose of estimating displacement impacts is given in Table 11.45   Open ▸ . Estimated abundances for projects are those presented by Berwick Bank (SSE Renewables, 2022), for which NatureScot has not raised any concerns or noted any errors. In addition, estimates have been obtained from Green Volt Offshore Wind Farm (Green Volt, 2023), Pentland Floating Offshore Wind (Pentland Floating Offshore Wind Farm, 2022), West of Orkney (Offshore Wind Power Limited, 2023), North Falls (North Falls, 2023), Five Estuaries (Five Estuaries, 2023) and Outer Dowsing (Outer Dowsing, 2023) offshore wind farms, as those projects had not published their estimates at the time of the Berwick Bank application.

 

Table 11.45:
Guillemot Cumulative Abundance Estimates

Table 11.45: Guillemot Cumulative Abundance Estimates

 

  1. The cumulative displacement mortality is given in Table 11.46   Open ▸ (with Berwick Bank included) and Table 11.47   Open ▸ (with Berwick Bank excluded). Mortality is calculated using 60% displacement and a range of 3% to 5% mortality in the breeding season and 1% to 3% mortality in the non-breeding season, in line with guidance (NatureScot, 2023h). Additionally, the Applicant’s Approach which utilises a 50% displacement rate and 1% mortality rate is presented.
Table 11.46:
Guillemot Cumulative Displacement Mortality Estimates Inclusive of Berwick Bank

Table 11.46: Guillemot Cumulative Displacement Mortality Estimates Inclusive of Berwick Bank

 

  1. With Berwick Bank, the estimated displacement mortality for guillemot, following the NatureScot Approach, is 2,406 to 4,010 individuals in the breeding season and 2,395 to 7,184 individuals in the non-breeding season. This is equivalent to an increase in baseline mortality of 1.98% to 3.29% in the breeding season and 1.12% to 3.35% in the non-breeding season. On an annual basis, the number of mortalities is estimated as 4,801 to 11,194 individuals, which equates to an increase in baseline mortality of 2.24% to 5.21% ( Table 11.46   Open ▸ ).
  2. When following the Applicant’s Approach, the estimated displacement mortality with Berwick Bank, for guillemot is 668 individuals in the breeding season and 1,995 individuals in the non-breeding season. This is equivalent to an increase in baseline mortality of 0.55% in the breeding season and 0.93% in the non-breeding season. On an annual basis, the number of mortalities is estimated as 2,664 individuals, which equates to an increase in baseline mortality of 1.24%.
  3. Without Berwick Bank, the estimated displacement mortality for guillemot, following the NatureScot Approach, is 1,071 to 1,786 individuals in the breeding season and 2,130 to 6,389 individuals in the non-breeding season. This is equivalent to an increase in baseline mortality of 0.88% to 1,47% in the breeding season and 0.92% to 2.98% in the post-breeding season. On an annual basis, the number of mortalities is estimated as 3,201 to 8,175 individuals, which equates to an increase in baseline mortality of 1.50% to 3.81% ( Table 11.47   Open ▸ ).

 

Table 11.47:
Guillemot Cumulative Displacement Mortality Estimates Exclusive of Berwick Bank

Table 11.47: Guillemot Cumulative Displacement Mortality Estimates Exclusive of Berwick Bank

 

  1. When following the Applicant’s Approach, the estimated displacement mortality with Berwick Bank, for guillemot is 298 individuals in the breeding season and 1,775 individuals in the non-breeding season. This is equivalent to an increase in baseline mortality of 0.25% in the breeding season and 0.83% in the non-breeding season. On an annual basis, the number of mortalities is estimated as 2,073 individuals, which equates to an increase in baseline mortality of 0.97%.
  2. The estimated cumulative displacement mortality therefore represents an increase in mortality of over 1% of baseline mortality, when including Berwick Bank or applying the NatureScot Approach range without Berwick Bank. Therefore, to further assess the significance of this effect, a PVA has been carried out for guillemot during the breeding season, non-breeding season and on an annual basis as described in volume 3, appendix 11.5.
                        PVA Assessment Including Berwick Bank
  1. When considering the impact during the breeding season on the regional population defined for the breeding season, using the NatureScot approach (60% displacement and 3% to 5% mortality) and with Berwick Bank included, the PVA predicted that the CPS was 0.299 to 0.130 (Table 11.48:). The median population size was therefore projected to be between 70.14% to 86.97% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 0. In terms of the population size, this implies that the median of the impacted population falls outside the percentile range of the unimpacted population (a value of 50 would indicate that they are the same). This suggests that this level of impact would have an adverse effect on the population, with an impact rate of 60% displacement and 3% to 5% mortality causing a population decline. However, as stated, the CPGR is considered a more robust metric compared to the CPS in this analysis due to the models being conducted with density independence, in line with NatureScot (2023k) guidance. The PVA model predicted that the CPGR was between 0.967 to 0.945 (Table 11.48:) which translates to a median reduction of 3.30% to 5.50% in population growth rate after 35 years. Such a decrease indicates that this level of impact would adversely affect the population. However, as noted earlier within section 11.11, research examining the displacement effects on guillemots indicates that a 50% displacement rate is more reflective, with this rate still regarded as precautionary (RoyalHaskoning, 2013; Peschko et al. 2020; APEM, 2022; MacArthur Green, 2023). Consequently, it is anticipated that the Applicant’s approach (incorporating a 50% displacement rate alongside a 1% mortality rate) leads to an estimate that aligns more closely with actual conditions. If the Applicant’s approach is followed, the increase in baseline mortality would be 0.55%. This level of impact would likely remain undetectable against natural population fluctuations. Furthermore, it would not significantly alter the background mortality rate.

 

Table 11.48:
Guillemot 35 Year Cumulative PVA Results for Displacement Impacts Including Berwick Bank during the Breeding Season

Table 11.48: Guillemot 35 Year Cumulative PVA Results for Displacement Impacts Including Berwick Bank during the Breeding Season

 

  1. When considering the impact during the non-breeding season on the regional population defined for the non-breeding season, using the NatureScot approach (60% displacement and 1% to 3% mortality) and with Berwick Bank included, the PVA predicted that the CPS was 0.904 to 0.739 ( Table 11.49   Open ▸ ). The median population size was therefore projected to be between 9.58% to 26.15% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 32.92 to 8.32. In terms of the population size, this implies that the median of the impacted population fell within the 32nd and 8th percentile of the unimpacted population (a value of 50 would indicate that they are the same). This suggests that, if a 60% displacement and 3% mortality rate was applied, this level of impact could have an adverse effect on the population. However, as stated, the CPGR is considered a more robust metric compared to the CPS in this analysis due to the models being conducted with density independence, in line with NatureScot (2023k) guidance. The PVA model predicted that the CPGR was between 0.997 to 0.992 ( Table 11.49   Open ▸ ) which translates to a median reduction of 0.28% to 0.84% in population growth rate after 35 years. Such a decrease indicates that this level of impact would not adversely affect the population and would likely remain undetectable against natural population fluctuations. Furthermore, it is not expected to significantly alter the background mortality rate. Additionally, as stated above, it is anticipated that the Applicant’s approach (incorporating a 50% displacement rate alongside a 1% mortality rate) leads to an estimate that aligns more closely with actual conditions. If the Applicant’s approach is followed, the increase in baseline mortality would be 0.93%. In addition, the guillemot population in the UK North Sea & Channel waters BDMPS is observed to be growing and the population is still expected to continue to grow and will be larger after 35 years than that which is currently recorded, even in the event of the largest impact.

 

Table 11.49:
Guillemot 35 Year Cumulative PVA Results for Displacement Impacts Including Berwick Bank during the Non-breeding Season

Table 11.49: Guillemot 35 Year Cumulative PVA Results for Displacement Impacts Including Berwick Bank during the Non-breeding Season

 

  1. When considering the annual impact on the annual regional population, under the NatureScot Approach (60% displacement and 1% to 3% mortality) and with Berwick Bank included, the PVA predicted that the CPS was 0.817 to 0.623 ( Table 11.50   Open ▸ ). The median population size was therefore projected to be between 18.31% to 37.71% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 17.72 to 1.52. In terms of the population size, this implies that the median of the impacted population fell within the 17th and 1st percentile of the unimpacted population (a value of 50 would indicate that they are the same). This suggests that, if a 60% displacement and 3% mortality rate was applied, this level of impact could have an adverse effect on the population. However, as stated, the CPGR is considered a more robust metric compared to the CPS in this analysis due to the models being conducted with density independence, in line with NatureScot (2023) guidance. The PVA model predicted that the CPGR was between 0.994 to 0.987 ( Table 11.50   Open ▸ ) which translates to a median reduction of 0.56% to 1.31% in population growth rate after 35 years. Such a decrease indicates that this level of impact could adversely affect the population. As stated previously, it is anticipated that the Applicant’s approach (incorporating a 50% displacement rate alongside a 1% mortality rate) leads to an estimate that aligns more closely with actual conditions. In addition, the guillemot population in the UK North Sea & Channel waters BDMPS is observed to be growing and the population is still expected to continue to grow and will be larger after 35 years than that which is currently recorded, even in the event of the largest impact.
  2. When following the Applicant’s Approach, the PVA predicted that the CPS was 0.894 ( Table 11.50   Open ▸ ). The median population size was therefore projected to be 10.60% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 31.04. In terms of the population size, this implies that the median of the impacted population fell within the 31st percentile of the unimpacted population (a value of 50 would indicate that they are the same). This suggests that the impacted scenario was still within the margin of error of the non-impacted scenario, and therefore there would likely be no adverse effect to the population. As stated the CPGR is considered a more robust metric compared to the CPS in this analysis due to the models being conducted with density independence, in line with NatureScot (2023) guidance. The PVA model predicted that the CPGR was 0.997 ( Table 11.50   Open ▸ ) which translates to a median reduction of 0.31% in population growth rate after 35 years. Such a decrease indicates that this level of impact would not adversely affect the population and would not trigger a risk of population decline and would only result in a slight reduction in the growth rate currently seen in the BDMPS population and would therefore be undetectable against natural population fluctuations. Furthermore, it is not expected to significantly alter the background mortality rate. In addition, the guillemot population in the UK North Sea & Channel waters BDMPS is observed to be growing and the population is still expected to continue to grow and will be larger after 35 years than that which is currently recorded, even in the event of the largest impact.

 

Table 11.50:
Guillemot 35 Year Cumulative PVA Results for Displacement Impacts Including Berwick Bank on an Annual Basis

Table 11.50: Guillemot 35 Year Cumulative PVA Results for Displacement Impacts Including Berwick Bank on an Annual Basis