PVA Assessment Excluding Berwick Bank
  1. When considering the impact during the pre-breeding season on the regional population defined for the pre-breeding season, using the NatureScot Approach (0.993 avoidance, 30% displacement and 1% to 3% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was between 0.892 to 0.860 ( Table 11.95   Open ▸ ). The median population size was therefore projected to be 10.79% to 14.02% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 43.04 to 40.68. In terms of the population size, this means that the median of the impacted population fell within the 43rd and 40th 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. 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 0.996 ( Table 11.95   Open ▸ ) which translates to a median reduction of 0.32% to 0.42% 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.
  2. When considering the impact during the pre-breeding season on the regional population defined for the pre-breeding season, using the Applicant’s displacement rates and the NatureScot avoidance rates (0.993 avoidance, 30% displacement and 1% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was 0.892 ( Table 11.95   Open ▸ ). The median population size was therefore projected to be 10.77% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 43.24. In terms of the population size, this means that the median of the impacted population fell within the 43rd 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. 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 0.997 ( Table 11.95   Open ▸ ) which translates to a median reduction of 0.32% 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.

 

Table 11.95:
Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Pre-breeding Season

Table 11.95: Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Pre-breeding Season

 

  1. When considering the impact during the breeding season on the regional population defined for the breeding season, using the NatureScot Approach (0.993 avoidance, 30% displacement and 1% to 3% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was between 0.730 to 0.675 ( Table 11.96   Open ▸ ). The median population size was therefore projected to be 27.02% to 32.46% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 30.04 to 26.00. In terms of the population size, this means that the median of the impacted population fell within the 30th and 26th 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 outlined within volume 3, appendix 11.5, 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 0.991 to 0.989 ( Table 11.96   Open ▸ ) which translates to a median reduction of 0.87% to 1.08% 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.
  2. When considering the impact during the breeding season on the regional population defined for the breeding season, using the Applicant’s displacement rates and the NatureScot avoidance rates (0.993 avoidance, 30% displacement and 1% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was 0.730 ( Table 11.96   Open ▸ ). The median population size was therefore projected to be 26.99% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 30.12. In terms of the population size, this means that the median of the impacted population fell within the 30th 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 (2023k) guidance. The PVA model predicted that the CPGR was 0.991 ( Table 11.96   Open ▸ ) which translates to a median reduction of 0.87% 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 11.96:
Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Breeding Season

Table 11.96: Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Breeding Season

 

  1. When considering the impact during the post-breeding season on the regional population defined for the post-breeding season, using the most extreme NatureScot scenario (0.993 avoidance, 30% displacement and 3% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was 0.876 ( Table 11.97   Open ▸ ). The median population size was therefore projected to be 12.37% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 42.20. In terms of the population size, this means that the median of the impacted population fell within the 42nd 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. 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 11.97   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 likely remain undetectable against natural population fluctuations. Furthermore, it is not expected to significantly alter the background mortality rate.

 

Table 11.97:
Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Post-breeding Season

Table 11.97: Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Post-breeding Season

 

  1. When considering the annual impact on the annual regional population, using the NatureScot Approach (0.993 avoidance, 30% displacement and 1% to 3% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was between 0.760 to 0.694 ( Table 11.98   Open ▸ ). The median population size was therefore projected to be between 24.02% to 30.56% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 33.60 to 28.68. In terms of the population size, this means that the median of the impacted population fell within the 33rd and 28th 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. 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 0.992 to 0.990 ( Table 11.98   Open ▸ ) which translates to a median reduction of 0.76% to 1.01% 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.
  2. When considering the annual impact on the annual regional population, using the Applicant’s displacement rate and the NatureScot avoidance rates (0.993 avoidance, 30% displacement and 1% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was 0.760 ( Table 11.98   Open ▸ ). The median population size was therefore projected to be 24.02% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 33.12. In terms of the population size, this means that the median of the impacted population fell within the 33rd 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. 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 0.992 ( Table 11.98   Open ▸ ) which translates to a median reduction of 0.76% 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 11.98:
Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank on an Annual Basis

Table 11.98: Kittiwake 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank on an Annual Basis

 

                        Magnitude of impact
  1. When considering both displacement and collision impacts in line with NatureScot guidance, there's a potential for double counting as a bird that is displaced cannot simultaneously experience collision. Therefore, it is likely that impacts provided within Table 11.89   Open ▸ to Table 11.90   Open ▸ are overestimates. As kittiwake experience around 30% displacement, collision numbers should be reduced by around 30%.
  2. Information surrounding kittiwake displacement is also limited and so it is unclear if kittiwake do indeed experience displacement effects and hence the numbers within Table 11.89   Open ▸ to Table 11.90   Open ▸ could be overestimates. If displacement is not included within the cumulative impacts or if displacement is accounted for (thus then reducing density within the wind farm and therefore reduce the number of collision), the magnitude of the impact is said to be low.
  3. Given the decline in kittiwake populations within the UK reported by Burnell et al. (2023), attributed to various pressures such as diminished prey resources impacting productivity (Furness and Tasker, 2000; Frederiksen et al., 2008; Carroll et al., 2017), and challenges from climate change (Heath et al., 2012), it is imperative that offshore wind farms do not exacerbate this decline further.
  4. Based on the PVA results for the pre-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude
  5. Based on the PVA results for the pre-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  6. Based on the PVA results for the pre-breeding season with Berwick Bank included and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  7. Based on the PVA results for the breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of medium magnitude
  8. Based on the PVA results for the breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of medium magnitude.
  9. Based on the PVA results for the breeding season with Berwick Bank included and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of medium magnitude.
  10. Based on the PVA results for the post-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  11. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  12. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank included and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  13. Based on the PVA results, on an annual basis with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of medium magnitude.
  14. Based on the PVA results, on an annual basis with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  15. Based on the PVA results, on an annual basis with Berwick Bank included and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  16. Based on the PVA results for the pre-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude
  17. Based on the PVA results for the pre-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  18. Based on the PVA results for the pre-breeding season with Berwick Bank excluded and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  19. Based on the PVA results for the breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  20. Based on the PVA results for the breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  21. Based on the PVA results for the breeding season with Berwick Bank excluded and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  22. Based on the PVA results for the post-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  23. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  24. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank excluded and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  25. Based on the PVA results, on an annual basis with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 3% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  26. Based on the PVA results, on an annual basis with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 30% displacement and 1% mortality rate, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  27. Based on the PVA results, on an annual basis with Berwick Bank excluded and following the Applicant Approach using a 30% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the kittiwake population is considered to be of low magnitude.
  28. The predicted impact with Berwick Bank included during the breeding season, using both the NatureScot and Applicant's Approach, would result in a medium magnitude of impact, which is significant in EIA terms.  However, if Berwick Bank is excluded, the cumulative impact on kittiwake populations from the remaining surrounding wind farms would result in a low magnitude of impact, deemed not significant in EIA terms.
  29. 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. With Berwick Bank included, the magnitude is considered to be medium. With Berwick Bank excluded, the magnitude is considered to be low.

                        Sensitivity of the receptor

  1. Kittiwake were assessed as having low vulnerability to displacement impacts but higher vulnerability to collision impacts, and therefore considered to have medium vulnerability to the combined impact of displacement and collision.
  2. 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.
  3. 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 conservation 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.
  4. Kittiwake is deemed to be of medium 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 with Berwick Bank included is deemed to be medium and the sensitivity of the receptor is considered to be high. The effect will, therefore, be of moderate to major adverse significance, which is significant in EIA terms. However, as the PVA results indicated that the magnitude was medium, the impact is considered moderate. It is therefore deemed appropriate to categorise the impact as having a moderate adverse significance, which is significant in EIA terms.
  2. The magnitude of the impact with Berwick Bank excluded 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, as PVA results indicated a low impact without Berwick Bank, the impact is considered minor. It is therefore deemed appropriate to categorise the impact as having a minor adverse significance, which is not significant in EIA terms.
                        Further mitigation and residual effect
  1. No offshore ornithology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 11.10) is not significant in EIA terms.
                        Gannet
  1. The combined cumulative collision and displacement mortality is given in Table 11.99   Open ▸ (with Berwick Bank included) and Table 11.100   Open ▸ (with Berwick Bank excluded). Displacement mortality is calculated using 70% displacement and a range of 1% to 3% mortality in all seasons, in line with guidance (NatureScot, 2023h). Additionally, the Applicant’s Approach which utilises a 70% displacement rate and 1% mortality rate is presented.

 

Table 11.99:
Gannet Combined Cumulative Displacement and Collision Mortality Estimates Inclusive of Berwick Bank

Table 11.99: Gannet Combined Cumulative Displacement and Collision Mortality Estimates Inclusive of Berwick Bank

 

  1. With Berwick Bank, the estimated combined displacement and collision mortality for gannet, following the NatureScot Approach, is 283 to 369 individuals in the pre-breeding season, 1,256 to 1,662 individuals in the breeding season and 855 to 1,218 individuals in the post-breeding season. This is equivalent to an increase in baseline mortality of 0.59% to 0.77% in the pre-breeding season, 0.85% to 1.13% in the breeding season and 0.97% to 1.39% in the post-breeding season. On an annual basis, the number of mortalities is estimated as 2,394 to 3,249 individuals, which equates to an increase in baseline mortality of 1.63% to 2.21% ( Table 11.99   Open ▸ ).
  2. When following the Applicant’s Approach, the estimated combined displacement and collision mortality with Berwick Bank, for gannet is 283 individuals in the pre-breeding season, 1,256 individuals in the breeding season and 855 individuals in the post-breeding season. This is equivalent to an increase in baseline mortality of 0.59% in the pre-breeding season, 0.85% in the breeding season and 0.97% in the post-breeding season. On an annual basis, the number of mortalities is estimated as 2,394 individuals, which equates to an increase in baseline mortality of 1.63%.

 

Table 11.100:
Gannet Combined Cumulative Displacement and Collision Mortality Estimates Exclusive of Berwick Bank

Table 11.100: Gannet Combined Cumulative Displacement and Collision Mortality Estimates Exclusive of Berwick Bank

 

  1. Without Berwick Bank, the estimated combined displacement and collision mortality for gannet, following the NatureScot Approach, is 278 to 360 individuals in the pre-breeding season, 1,053 to 1,393 individuals in the breeding season and 826 to 1,169 individuals in the post-breeding season. This is equivalent to an increase in baseline mortality of 0.58% to 0.75% in the pre-breeding season, 0.72% to 0.95% in the breeding season and 0.94% to 1.33% in the post-breeding season. On an annual basis, the number of mortalities is estimated as 1,466 to 1,986 individuals, which equates to an increase in baseline mortality of 1.47% to 1.99% ( Table 11.100   Open ▸ ).
  2. The cumulative combined displacement and collision mortality represents an increase in mortality of over 1% of baseline mortality, both with and without Berwick Bank. Therefore, to further assess the significance of this effect, a PVA has been carried out for gannet 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 most extreme NatureScot scenario (0.993 avoidance, 70% displacement and 3% mortality) and with Berwick Bank included, the PVA predicted that the CPS was 0.846 ( Table 11.101   Open ▸ ). The median population size was therefore projected to be 15.43% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 23.76. In terms of the population size, this means that the median of the impacted population fell within the 23rd 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. 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 0.995 ( Table 11.101   Open ▸ ) which translates to a median reduction of 0.46% 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.

 

Table 11.101:
Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank during the Breeding Season

Table 11.101: Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank during the Breeding Season

 

  1. When considering the impact during the post-breeding season on the regional population defined for the post-breeding season, using the NatureScot scenarios (0.993 avoidance, 70% displacement and 1% to 3% mortality) and with Berwick Bank included, the PVA predicted that the CPS was 0.807 ( Table 11.102   Open ▸ ). The median population size was therefore projected to be 19.26% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 19.72. In terms of the population size, this means that the median of the impacted population fell within the 19th percentile of the unimpacted population (a value of 50 would indicate that they are the same). This suggests that under a 70% displacement and 1% mortality rate alongside collision, 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. A percentile of 19 suggests that an adverse effect could occur. 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 0.994 ( Table 11.102   Open ▸ ) which translates to a median reduction of between 0.59% 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.

 

Table 11.102:
Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank during the Post-breeding Season

Table 11.102: Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank during the Post-breeding Season

 

  1. When considering the annual impact on the annual regional population, using the NatureScot Approach (0.993 avoidance, 70% displacement and 1% to 3% mortality) and with Berwick Bank included, the PVA predicted that the CPS was between 0.785 to 0.720 ( Table 11.103   Open ▸ ). The median population size was therefore projected to be between 21.46% to 27.98% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 15.80 to 9.64. In terms of the population size, this means that the median of the impacted population fell within the 15th and 9th percentile of the unimpacted population (a value of 50 would indicate that they are the same). Notably, the median of the impacted population fell close to the lower boundary, between the 15th and 9th percentiles of the unimpacted population. Whilst this is within the margin of error, this proximity suggests there could be an 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 between 0.993 to 0.991 ( Table 11.103   Open ▸ ) which translates to a median reduction of 0.67% to 0.91% 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.
  2. When considering the annual impact on the annual regional population, using the Applicant’s displacement rate and the NatureScot avoidance rates (0.993 avoidance, 70% displacement and 1% mortality) and with Berwick Bank included, the PVA predicted that the CPS was 0.785 ( Table 11.103   Open ▸ ). The median population size was therefore projected to be 21.47% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 15.88. In terms of the population size, this means that the median of the impacted population fell within the 15th percentile of the unimpacted population (a value of 50 would indicate that they are the same). Notably, the median of the impacted population fell close to the lower boundary of the 15th percentile of the unimpacted population. Whilst this is within the margin of error, this proximity suggests there could be an 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 0.993 ( Table 11.103   Open ▸ ) which translates to a median reduction of 0.67% 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 11.103:
Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank on an Annual Basis

Table 11.103: Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank on an Annual Basis

 

                        PVA Assessment Excluding Berwick Bank
  1. When considering the impact during the post-breeding season on the regional population defined for the post-breeding season, using the most extreme NatureScot scenario (0.993 avoidance, 70% displacement and 3% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was 0.814 ( Table 11.104   Open ▸ ). The median population size was therefore projected to be 18.58% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 20.56. In terms of the population size, this means that the median of the impacted population fell within the 20th 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. 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 0.994 ( Table 11.104   Open ▸ ) which translates to a median reduction of 0.57% 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.

 

Table 11.104:
Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Post-breeding Season

Table 11.104: Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Excluding Berwick Bank during the Post-breeding Season

 

  1. When considering the annual impact on the annual regional population, using the Applicant’s Approach (0.993 avoidance, 70% displacement and 1% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was between 0.804 to 0.739 ( Table 11.105   Open ▸ ). The median population size was therefore projected to be between 19.56% to 26.08% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 18.56 to 11.08. In terms of the population size, this means that the median of the impacted population fell within the 18th and 11th percentile of the unimpacted population (a value of 50 would indicate that they are the same). Notably, the median of the impacted population fell close to the lower boundary, between the 18th and 11th percentiles of the unimpacted population. Whilst this is within the margin of error, this proximity suggests there could be an 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 between 0.994 to 0.992 ( Table 11.105   Open ▸ ) which translates to a median reduction of 0.60% 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 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.
  2. When considering the annual impact on the annual regional population, using the Applicant’s displacement rate and the NatureScot avoidance rates (0.993 avoidance, 70% displacement and 1% mortality) and with Berwick Bank excluded, the PVA predicted that the CPS was 0.804 ( Table 11.105   Open ▸ ). The median population size was therefore projected to be 19.57% smaller than the unimpacted population over a 35 year time period, with a 50th centile value of 18.44. In terms of the population size, this means that the median of the impacted population fell within the 18th percentile of the unimpacted population (a value of 50 would indicate that they are the same). Notably, the median of the impacted population fell close to the lower boundary of the 18th percentile of the unimpacted population. Whilst this is within the margin of error, this proximity suggests there could be an 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 0.994 ( Table 11.105   Open ▸ ) which translates to a median reduction of 0.60% 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 11.105:
Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank on an Annual Basis

Table 11.105: Gannet 35 Year Cumulative PVA Results for Combined Displacement and Collision Impacts Including Berwick Bank on an Annual Basis

 

                        Magnitude of impact
  1. When considering both displacement and collision impacts in line with NatureScot guidance, there's a potential for double counting as a bird that is displaced cannot simultaneously experience collision. Therefore, it is likely that impacts provided within Table 11.99   Open ▸ to Table 11.100   Open ▸ are overestimates. As gannet experience around 70% displacement, collision numbers should be reduced by around 70%.
  2. Based on the combined displacement and collision assessment for the pre-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude
  3. Based on the combined displacement and collision assessment for the pre-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  4. Based on the combined displacement and collision assessment for the pre-breeding season with Berwick Bank included and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  5. Based on the PVA results for the breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  6. Based on the combined displacement and collision assessment for the breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  7. Based on the combined displacement and collision assessment for the breeding season with Berwick Bank included and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  8. Based on the PVA results for the post-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  9. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  10. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank included and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  11. Based on the PVA results, on an annual basis with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  12. Based on the PVA results, on an annual basis with Berwick Bank included and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  13. Based on the PVA results, on an annual basis with Berwick Bank included and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  14. Based on the combined displacement and collision assessment for the pre-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude
  15. Based on the combined displacement and collision assessment for the pre-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  16. Based on the combined displacement and collision assessment for the pre-breeding season with Berwick Bank excluded and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  17. Based on the combined displacement and collision assessment for the breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  18. Based on combined displacement and collision assessment results for the breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  19. Based on the combined displacement and collision assessment for the breeding season with Berwick Bank excluded and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  20. Based on the PVA results for the post-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  21. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  22. Based on the combined displacement and collision assessment for the post-breeding season with Berwick Bank excluded and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  23. Based on the PVA results, on an annual basis with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 3% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  24. Based on the PVA results, on an annual basis with Berwick Bank excluded and following the NatureScot Approach using a 0.993 avoidance rate and a 70% displacement and 1% mortality rate, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  25. Based on the PVA results, on an annual basis with Berwick Bank excluded and following the Applicant Approach using a 70% displacement and 1% mortality rate and using the NatureScot avoidance rate of 0.993, the impact from the cumulative assessment on the gannet population is considered to be of low magnitude.
  26. Results from the PVA for the breeding, post-breeding season and annually concluded that the impact from the cumulative assessment with Berwick Bank included and excluded and following both the NatureScot and Applicant’s Approach was perceived as low.
  27. 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. Gannet were assessed as having low vulnerability to displacement impacts but higher vulnerability to collision impacts, and therefore considered to have medium vulnerability to the combined impact of displacement and collision.
  2. Gannet 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 6.30 of volume 3, appendix 11.1 for details of SPAs with connectivity to the Array with regards to gannet.
  3. Gannet have low reproductive potential given a typical age of first breeding of five years and typically laying only a single egg per breeding season. However, although gannet has a low reproductive potential, the species has demonstrated a consistent increasing trend in abundance since the 1990’s (JNCC, 2020). It is of note that the species has suffered from the outbreak of HPAI during the 2022 breeding season (Pearce-Higgins et al., 2023), with declines of 25% recorded at certain sites in Britain in 2023 when compared against a pre-HPAI baseline (Tremlett et al., 2024). Therefore, whilst the overall population has shown steady growth, HPAI has led to some short-term declines. Therefore, overall gannet is deemed to have low recoverability.
  4. Gannet is deemed to be of medium vulnerability, medium 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, considering the pre-breeding, season mortality rates fell below 1%, along with the 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.
                        Further mitigation and residual effect
  1. No offshore ornithology mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in section 11.10) is not significant in EIA terms.