5.5. Assessment of Adverse Effects in-Combination with other Plans and Projects

As detailed in section 4.6, certain impacts were excluded from further consideration if their assessment at the project level indicated negligible effects, deeming them inconsequential to any meaningful contribution to an existing cumulative impact. Following the alone assessment, the following effect pathways were excluded from the in-combination assessment:

factors such as changes to prey availability, entanglement, migratory collision risk, migratory barrier effect and artificial lighting, though acknowledged for their potential cumulative effects, are deemed insignificantly impactful at a population level for offshore ornithology receptors;
displacement of seabirds during the construction phase due to the potential impacts and effects predicted for the Array being negligible/ minor at most and are spatially and temporally restricted; and
all impacts during decommissioning, as potential impacts are predicted to be negligible, and there is limited data or low confidence in data regarding other plans and projects related to this potential impact source.

Sites and features were included within the in-combination assessment if any of the following criteria were met during the alone assessment:

the Array alone impact from displacement and/or collision at the Array is greater than or equal to one individual per year (following the most precautionary approach to assessment); and/or
the Array alone impact at the Array results in an increase in mortality rate of greater than or equal to 0.02 percentage points; and/or
an Appropriate Assessment for one or more of the other considered plans has identified a potential AEOI to the feature.

If none of the above criteria are met, it was concluded, beyond reasonable scientific doubt, that the Array, in combination with other plans or projects, does not pose any potential for an AEOI.
Based on the evaluation of the Array alone (section 5.4) and the above criteria, it was concluded that the only impact pathways for which there is the potential for an in-combination effect are disturbance and displacement, and collision risk. A potential in-combination effect has only been identified during the operation and maintenance phase.
The sites, features and impacts that require an in-combination assessment are presented in Table 5.61 Open ▸ .

Table 5.61: Assessment of Features of SPA or Ramsar sites Requiring In-Combination Assessment

The sites that do not meet any of the criteria set out in paragraph 351 are:

Copinsay SPA;
Fair Isle SPA;
North Rona and Sula Sgeir SPA;
Outer Firth of Forth and St Andrew’s Bay Complex SPA;
Sule Skerry and Sule Stack SPA;
Cameron Reservoir SPA and Ramsar site;
Din Moss - Hoselaw Loch SPA and Ramsar site;
Fala Flow SPA and Ramsar site;
Firth of Forth SPA and Ramsar site;
Firth of Tay and Eden Estuary SPA and Ramsar site;
Gladhouse Reservoir SPA and Ramsar site;
Greenlaw Moor SPA and Ramsar site;
Holburn Lake and Moss SPA and Ramsar site;
Lindisfarne SPA and Ramsar site;
Loch of Kinnordy SPA and Ramsar site;
Loch Leven SPA and Ramsar site;
Montrose Basin SPA and Ramsar site;
Northumbria Coast SPA and Ramsar site;
Slamannan Plateau SPA;
South Tayside Goose Roosts SPA and Ramsar site;
Westwater SPA and Ramsar site; and
Ythan Estuary, Sands of Forvie and Meikle Loch SPA, Ythan Estuary and Meikle Loch Ramsar site.

For all these sites, as set out above, it has been demonstrated that that Array will not make a meaningful contribution to any cumulative impact, and therefore it is concluded beyond reasonable scientific doubt that the Array will not cause an AEOI to any of those sites.

5.5.1. In-combination data sources

The in-combination assessment for ornithology requires the mortality from each other relevant project apportioned to the SPA or Ramsar site being assessed. Primarily, this has been drawn from the recent Berwick Bank Offshore Wind Farm RIAA (SSE Renewables, 2022) as the most comprehensive recent compilation. It should be noted that Berwick Bank Offshore Wind Farm do not provide in-combination values for individual projects but totalled for the UK North Sea region. Where values were not available from Berwick Bank Offshore Wind Farm, other data sources were used as necessary.
In addition, project-alone values for more recent applications have been added to the Berwick Bank Offshore Wind Farm totals, specifically Green Volt Offshore Wind Farm (Green Volt Offshore Wind Farm, 2023), West of Orkney Wind Farm (Offshore Wind Power Limited, 2023), Pentland Floating Offshore Wind (Xodus Group Ltd, 2022), Five Estuaries Offshore Windfarm (Five Estuaries Wind Farm Ltd, 2023), Outer Dowsing Offshore Wind (Outer Dowsing Offshore Wind, 2023) and Sheringham Shoal and Dudgeon Offshore Wind Farm Extension Projects (hereafter SEP & DEP) (Equinor, 2022, 2023). As quantitative information for these projects was not available at the time Berwick Bank Offshore Wind Farm was compiling its assessment, values for these projects are not included in the UK North Sea totals presented by Berwick Bank Offshore Wind Farm.
The number of mortalities for other projects is dependent on the approach used for assessment. There is scope for this to vary, for example using different displacement rate/mortality rates to assess distributional responses, or different avoidance rates to assess collision mortality. Typically, more than one approach is presented to give a range of plausible impact mortalities. In particular, Berwick Bank Offshore Wind Farm followed a “dual approach” to assessment, presenting both a “Scoping Approach” (following advice from SNCBs, as presented in the NatureScot guidance notes) and a “Developer Approach” (the preferred approach of that project’s developer). Where the Scoping Approach is used to assess a range of impacts, the lower and upper end of that range are distinguished as “Scoping A” and “Scoping B” respectively. For more details on the approaches to assessment used in previous assessments, refer to the source document referenced (SSE Renewables, 2022).
This in-combination assessment presents the full range of impact mortalities, as presented in the source material, and from that range considers the lowest value and the highest value presented for each other project (identified here as the approach applied by each project), in order to create a “low” approach total (which is typically either the project applicant’s preferred approach or the lower end of the SNCB approach) and a ”high” approach total (typically the more precautionary end of the SNCB approach).
Where quantitative assessment is not available in the source data for a project for a feature/site, this is shown as “N/A” in the tables in each assessment. If no quantitative information is available, this is indicative that the source assessment concluded, beyond reasonable scientific doubt, that the project had either no connectivity or a negligible impact on the feature/site.
In line with NatureScot’s comments on the Offshore HRA Screening Report (Ossian OWFL, 2023) ( Table 2.1 Open ▸ ), the assessment has been carried out both including impacts from Berwick Bank Offshore Wind Farm and excluding those impacts. Where the in-combination totals are sources from the Berwick Bank Offshore Wind Farm RIAA (SSE Renewables, 2022), Berwick Bank Offshore Wind Farm’s own impact is included in the UK North Sea regional totals (with the contribution from each project drawing on public domain information). Therefore, the scenario excluding impacts from Berwick Bank Offshore Wind Farm is calculated by simply subtracting the Berwick Bank Offshore Wind Farm alone impacts from the UK North Sea regional total (with results presented as low and high, based in the Berwick Bank Offshore Wind Farm Developer and Scoping B approaches).

Addendum: Green Volt Decision

It is noted that towards the finalisation of this RIAA, a decision on the Green Volt Offshore Wind Farm application was published, with consent granted by the Scottish Ministers (Scottish Government, 2024). Before reaching this decision, the Scottish Ministers carried out an Appropriate Assessment (Appendix B of Scottish Government, 2024) and concluded that an AEOI in-combination is either expected or cannot be ruled out for the following SPA and feature combinations that are relevant for the Array assessment:

Kittiwake at Buchan Ness to Collieston Coast SPA;
Kittiwake, guillemot and razorbill at East Caithness Cliffs SPA;
Gannet and puffin at Forth Islands SPA;
Kittiwake at Fowlsheugh SPA; and
Kittiwake at Troup, Pennan and Lion’s Head SPA.

Green Volt Offshore Wind Farm will be required to carry out compensation to mitigate its impact for all sites and features where an AEOI was not ruled out in the Appropriate Assessment (Appendix B of Scottish Government, 2024). Therefore, for those features, the net impact from Green Volt Offshore Wind Farm following compensation may be deemed to be zero. However, as this decision was published during the time that the in-combination assessments for the Array were undertaken in this RIAA, the in-combination totals for Green Volt Offshore Wind Farm have not been amended to reflect this requirement for compensation, and the predicted impact from Green Volt Offshore Wind Farm prior to compensation (as per Green Volt Offshore Wind Farm, 2023) have been included in the calculation of in-combination total impact values. Therefore, the totals presented in this RIAA for those features listed in paragraph 363 must be considered to have an extra element of precaution, as a result of the inclusion of impacts which will be compensated for. It is noted that the impacts from Green Volt Offshore Wind Farm alone tend to be a small proportion of the in-combination totals and therefore it is not anticipated that this degree of precaution would influence the conclusions and the determination of AEOI or no AEOI.

5.5.2. Disturbance and Displacement

Operation and Maintenance Phase

During the operational phase, seabirds may be impacted by a disturbance and/or displacement due to the physical presence of wind turbines, vessel traffic and helicopter activity. Disturbance and/or displacement may have consequent impacts on the survival or fitness of birds. If displacement limits seabird access to foraging areas, it can result in reduced energy intake and reduced foraging success. Displacement effects can also cause increased inter- and intra-specific competition for alternative foraging areas and prey resources.
The displacement and subsequent mortality rates used for the Array are given in Table 5.3 Open ▸ , although for this in-combination assessment, only the lowest and highest approach are taken through to assess the total range of impacts. For other developments, the displacement and mortality rates are as described in the data source referenced in each case.

Buchan Ness to Collieston Coast SPA

Kittiwake (seabird assemblage component only)

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.62 Open ▸ .

Table 5.62: Kittiwake Displacement Mortalities Apportioned to the Buchan Ness to Collieston Coast SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.63 Open ▸ .

Table 5.63: Kittiwake Displacement Mortalities Apportioned to the Buchan Ness to Collieston Coast SPA In-Combination Totals

With a population of 22,590 breeding adults (Burnell et al., 2023), 7.8 to 20.3 additional mortalities represents a 0.035 to 0.090 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.64 Open ▸ . Full details are available in appendix 3B.

Table 5.64: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the Buchan Ness to Collieston Coast SPA

The kittiwake population of the Buchan Ness to Collieston Coast SPA has declined significantly between its citation level of 60,904 breeding adults and Seabird Census counts of 22,590 breeding adults (Burnell et al., 2023), and is assessed as being in “Unfavourable No Change” condition (NatureScot, ND). There have however been recent signs of slight recovery, with 13,547 AONs (27,094 individuals) recorded in 2023 (Tremlett et al, 2024).
The PVA results show that the kittiwake population is expected to remain relatively stable under the counterfactual (no impact) scenario and also under all impact scenarios considered. The median Counterfactual of Growth Rate (CGR) is, for all scenarios, at least 0.999 which indicates the population growth rate declines no more than 0.1%. After 35 years (the expected lifespan of the Array), the Counterfactual of Population Size (CPS) ranges from 0.963 (with Berwick Bank Offshore Wind Farm; High approach to assessment) to 0.986 (without Berwick Bank Offshore Wind Farm; Low approach to assessment).
Overall, therefore, the impact of displacement from the Array in combination with other projects is not of a magnitude that can be said to adversely affect the likelihood of the kittiwake population being maintained as a viable component of the site.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, kittiwake was the only species for which a potential LSE2 was identified. As detailed above, there is expected to be no significant impact on the kittiwake population. Therefore, it can also be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the Buchan Ness to Collieston Coast SPA as a result of displacement from the Array in combination with other developments.

Coquet Island SPA

Puffin (seabird assemblage component only)

The source information regarding puffin disturbance mortality from other relevant projects is given in Table 5.65 Open ▸ .

Table 5.65: Puffin Disturbance Mortalities Apportioned to the Coquet Island SPA From Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.66 Open ▸ .

Table 5.66: Puffin Displacement Mortalities Apportioned to the Coquet Island SPA In-Combination Totals

With a population of 50,058 breeding adults (Burnell et al., 2023), 3.3 to 42.1 additional mortalities represents a 0.007 to 0.084 percentage point increase in mortality rates. Therefore, PVA has been carried out to further assess the total in-combination impact.
The PVA results are summarised in Table 5.67 Open ▸ . Full details are available in appendix 3B.

Table 5.67: Summary of PVA Results for In-Combination Displacement Impacts on Puffin at the Coquet Island SPA

The puffin population of the Coquet Island SPA has increased significantly between its citation level of 31,686 breeding adults and recent counts of 50,058 breeding adults (Burnell et al., 2023).
Whilst the PVA results indicate a significant population decline from the current level even under the counterfactual scenario, given the positive growth observed at this site in recent years, that outcome is considered implausible for this site and so the assessment relies on the CPS and CGR. The limitations of the PVA model and available demographic parameters to specify as inputs mean that CPS and CGR are considered the most reliable metrics, as further detailed in appendix 3B. The median CGR is, for all scenarios and approaches, 0.999 to 1.000 which indicates the population growth rate declines by 0.1% or less. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.965 to 0.997. Overall, therefore, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the puffin population compared to the counterfactual scenario.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, puffin was the only species for which a potential LSE2 was identified. As detailed above, there is expected to be no significant impact on the puffin population. Therefore, it can also be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the Coquet Island SPA as a result of displacement from the Array in combination with other developments.

East Caithness Cliffs SPA

Kittiwake

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.68 Open ▸ .

Table 5.68: Kittiwake Displacement Mortalities Apportioned to the East Caithness Cliffs SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.69 Open ▸ .

Table 5.69: Kittiwake Displacement Mortalities Apportioned to the East Caithness Cliffs SPA In-Combination Totals

With a population of 48,958 breeding adults (Burnell et al, 2023), 55.0 to 179.7 additional mortalities represent a 0.112 to 0.367 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.70 Open ▸ . Full details are available in appendix 3B.

Table 5.70: Summary of PVA results for In-Combination Displacement Impacts on Kittiwake at the East Caithness Cliffs SPA

The kittiwake population of the East Caithness Cliffs SPA has declined slightly from its citation level of 65,000 breeding adults, with recent counts of 48,958 breeding adults (Burnell et al., 2023), although it is assessed as being in “Favourable Maintained” condition (NatureScot, ND).
The PVA results show that the kittiwake population is expected to remain relatively stable under the counterfactual (no impact) scenario. Under the impacted scenarios, the CGR is 0.999 under the “low” approach (whether including or excluding the impact of Berwick Bank Offshore Wind Farm) and 0.996 under the “high” approach (whether including or excluding the impact of Berwick Bank Offshore Wind Farm). This leads to a CPS after 35 years of 0.855 to 0.954 – i.e. the population size would be 4.6% to 14.5% smaller than the counterfactual population size.
Whilst this level of impact is small, it is not negligible and in the context of a population that is already declining, the additional mortality from the Array in combination with other projects and plans would appear to have the potential to adversely affect the likelihood of the site meeting its conservation objectives for all assessment scenarios and both with and without Berwick Bank Offshore Wind Farm. Therefore, it is concluded that there is a potential AEOI to the kittiwake feature of the East Caithness Cliffs SPA as a result of displacement impacts from the Array in-combination with other developments.

Breeding Seabird Assemblage

Of the components of the breeding seabird assemblage at the East Caithness Cliffs, only kittiwake was deemed to have any potential LSE2 ( Table 3.1 Open ▸ ). It is concluded (above) that there is a potential for an AEOI on the kittiwake feature as a result of the Array in-combination with other developments.
However, whilst there might be a negative effect on the kittiwake population, the magnitude of that effect is small. It is not considered a sufficiently large effect that it could be said to adversely affect the probability of kittiwake being maintained as a viable component of the seabird assemblage. Furthermore, as kittiwake is the only species being significantly impacted, it could not be said to adversely affect the probability of the total seabird assemblage being maintained. Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the East Caithness Cliffs SPA resulting from the impact of displacement from the Array in-combination with other developments.

Farne Islands SPA

Kittiwake (seabird assemblage component only)

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.71 Open ▸ .

Table 5.71: Kittiwake Displacement Mortalities Apportioned to the Farne Islands SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.72 Open ▸ .

Table 5.72: Kittiwake Displacement Mortalities Apportioned to the Farne Islands SPA In-Combination Totals

With a population of 8,804 breeding adults (Burnell et al, 2023), 2.2 to 15.4 additional mortalities represents a 0.025 to 0.175 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.73 Open ▸ . Full details are available in appendix 3B.

Table 5.73: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the Farne Islands SPA

The kittiwake population of the Farne Islands SPA has increased slightly from its citation level of 8,241 breeding adults to recent counts of 8,804 breeding adults (Burnell et al., 2023).
The PVA results show that the kittiwake population is expected to remain relatively stable under the counterfactual (no impact) scenario. Under the impacted scenarios, the CGR is 0.998 to 1.000. This leads to a CPS after 35 years of 0.928 to 0.989 – i.e. the population size would be 1.1% to 7.2% smaller than the counterfactual population size.
Overall, therefore, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the kittiwake population compared to the counterfactual scenario.

Puffin (seabird assemblage component only)

The source information regarding puffin disturbance mortality from other relevant projects is given in Table 5.74 Open ▸ .

Table 5.74: Puffin Disturbance Mortalities Apportioned to the Farne Islands SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.75 Open ▸ .

Table 5.75: Puffin Displacement Mortalities Apportioned to the Farne Islands SPA In-Combination Totals

With a population of 87,504 breeding adults (Burnell et al., 2023), 6.2 to 74.4 additional mortalities represents a 0.007 to 0.085 percentage point increase in mortality rates. Therefore, PVA has been carried out to further assess the total in-combination impact.
The PVA results are summarised in Table 5.76 Open ▸ . Full details are available in appendix 3B.

Table 5.76: Summary of PVA Results for In-Combination Displacement Impacts on Puffin at the Farne Islands SPA

The puffin population of the Farne Islands SPA has increased between its citation level of 76,798 breeding adults and recent counts of 87,504 breeding adults (Burnell et al., 2023).
Whilst the PVA results indicate a substantial population decline from the current level, given the growth observed at this site in recent years, that outcome is considered implausible for this site and so the assessment relies on the CPS and CGR. The limitations of the PVA model and available demographic parameters to specify as inputs mean that CPS and CGR are considered the most reliable metrics, as further detailed in appendix 3B. The median CGR is, for all scenarios and approaches, 0.999 to 1.000 which indicates the population growth rate declines no more than 0.1%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.965 to 0.997. Overall, therefore, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the puffin population compared to the counterfactual scenario.

Breeding Seabird Assemblage

The assessments carried out above conclude that there is no material impact resulting from displacement on the puffin or kittiwake components of the breeding seabird assemblage at the Farne Islands SPA. No other component was found to have any potential for a LSE2. Therefore, it can be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the Farne Islands SPA as a result of displacement impacts from the Array in-combination with other developments.

Flamborough and Filey Coast SPA

Kittiwake

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.77 Open ▸ .

Table 5.77: Kittiwake Displacement Mortalities Apportioned to the Flamborough and Filey Coast SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.78 Open ▸ .

Table 5.78: Kittiwake Displacement Mortalities Apportioned to the Flamborough and Filey Coast SPA In-Combination Totals

With a population of 91,008 breeding adults (Burnell et al, 2023), 19.0 to 71.2 additional mortalities represents a 0.021 to 0.078 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.79 Open ▸ . Full details are available in appendix 3B.

Table 5.79: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the Flamborough and Filey Coast SPA

The kittiwake population of the Flamborough and Filey Coast SPA has increased slightly from its citation level of 89,040 breeding adults to recent counts of 91,008 breeding adults (Burnell et al., 2023).
The PVA results show that the kittiwake population is expected to remain relatively stable under the counterfactual (no impact) scenario. Under the impacted scenarios, the CGR is 0.999 to 1.000. This leads to a CPS after 35 years of 0.967 to 0.991 – i.e. the population size would be 0.9% to 3.3% smaller than the counterfactual population size.
Overall, therefore, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the kittiwake population compared to the counterfactual scenario, and it can be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI on the kittiwake feature of the Flamborough and Filey Coast SPA as a result of displacement from the Array in-combination with other developments.

Gannet

The source information regarding gannet disturbance mortality from other relevant projects is given in Table 5.80 Open ▸ .

Table 5.80: Gannet Displacement Mortalities Apportioned to the Flamborough and Filey Coast SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.81 Open ▸ .

Table 5.81: Gannet Displacement Mortalities Apportioned to the Flamborough and Filey Coast SPA In-Combination Totals

With a population of 26,784 breeding adults (Burnell et al, 2023), 73.3 to 213.5 additional mortalities represents a 0.274 to 0.797 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.82 Open ▸ . Full details are available in appendix 3B.

Table 5.82: Summary of PVA Results for In-Combination Displacement Impacts on Gannet at the Flamborough and Filey Coast SPA

The gannet population of the Flamborough and Filey Coast SPA has increased between its citation level of 16,938 breeding adults and recent counts of 26,784 breeding adults (Burnell et al., 2023).
Under the “low” approach, the median CGR is 0.997 (whether including or excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines no more than 0.3%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.889 to 0.890.
Under the “high” approach, the median CGR is 0.991 (whether including or excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines by 0.9% compared to the counterfactual. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.713 to 0.715.
Under either approach, the level of impact is small, but considered of sufficient magnitude to be distinguishable from natural fluctuations. However, given that the gannet population of the Flamborough and Filey Coast SPA has increased from its citation level, the magnitude of impact is insufficient to create an impact that could be said to have an adverse effect on the population continuing to meet the site’s conservation objectives relating to maintaining the species’ population abundance.
Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the gannet feature of the Flamborough and Filey Coast SPA as a result of displacement from the Array in combination with other assessments.

Breeding Seabird Assemblage

Of the components of the breeding seabird assemblage, only kittiwake and gannet were found to have any potential LSE2. Guillemot was also screened in at the request of Natural England, but following the advice in NatureScot (2023d), no impact from the Array is apportioned to guillemots breeding at Flamborough and Filey Coast SPA. The assessments carried out for kittiwake and gannet (above) conclude there is no adverse effect on those features resulting from the displacement impact of the Array in-combination with other developments.
Therefore, it is also concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the breeding seabird assemblage feature of the Flamborough and Filey Coast SPA as a result of displacement from the Array in combination with other assessments.

Forth Islands SPA

Kittiwake (seabird assemblage component only)

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.83 Open ▸ .

Table 5.83: Kittiwake Displacement Mortalities Apportioned to the Forth Islands SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.84 Open ▸ .

Table 5.84: Kittiwake Displacement Mortalities Apportioned to the Forth Islands SPA In-Combination Totals

With a population of 9,084 breeding adults (Burnell et al, 2023), 7.7 to 33.7 additional mortalities represents a 0.085 to 0.371 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.85 Open ▸ . Full details are available in appendix 3B.

Table 5.85: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the Forth Islands SPA

The kittiwake population of the Forth Islands SPA has decreased between its citation level of 16,800 breeding adults and recent counts of 9,084 breeding adults (Burnell et al., 2023).
The PVA results show that the kittiwake population is expected to remain relatively stable under the counterfactual (no impact) scenario. Under the impacted scenarios, the CGR is 0.996 to 0.999. This leads to a CPS after 35 years of 0.853 to 0.964 – i.e. the population size would be 3.6% to 14.7% smaller than the counterfactual population size.
Under the “low” approach, whether or not Berwick Bank Offshore Wind Farm is included, the magnitude of the impact is considered to be negligible. However, under the “high” approach, the impact, whilst small, is of a magnitude that cannot be considered negligible. Given the population has already declined from its citation level, even this small impact has the potential to adversely affect the kittiwake population. However, kittiwake is not a qualifying feature it its own right, and instead only qualifies as a named component of the breeding seabird assemblage.

Puffin

The source information regarding puffin disturbance mortality from other relevant projects is given in Table 5.86 Open ▸ .

Table 5.86: Puffin Disturbance Mortalities Apportioned to the Forth Islands SPA from Other Relevant Projects

*Apportioned impacts only presented on an annual basis in source document.

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.87 Open ▸ .

Table 5.87: Puffin Displacement Mortalities Apportioned to the Forth Islands SPA In-Combination Totals

With a population of 85,846 breeding adults (Burnell et al., 2023), 46.7 to 294.2 additional mortalities represents a 0.054 to 0.343 percentage point increase in mortality rates. Therefore, PVA has been carried out to further assess the total in-combination impact.
The PVA results are summarised in Table 5.88 Open ▸ . Full details are available in appendix 3B.

Table 5.88: Summary of PVA Results for In-Combination Displacement Impacts on Puffin at the Forth Islands SPA

The puffin population of the Forth Islands SPA has increased between its citation level of 28,000 breeding adults and recent counts of 87,504 breeding adults (Burnell et al., 2023).
Whilst the PVA results indicate a significant population decline from the current level, given the beneficial growth observed at this site in recent years, that outcome is considered implausible for this site and so the assessment relies on the CPS and CGR, as explained in appendix 3B.
Under the “low” approach, the median CGR is 0.999 (whether including or excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines no more than 0.1%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.975 to 0.977. Overall, therefore, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the puffin population compared to the counterfactual scenario.
Under the “high” approach, the median CGR is 0.996 (whether including or excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines by 0.4% compared to the counterfactual. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.865 to 0.878. This level of impact is small, but considered of sufficient magnitude to be distinguishable from natural fluctuations. However, given that the puffin population of the Forth Islands SPA has increased dramatically, the magnitude of impact is insufficient to create an impact that could be said to have an adverse effect on the population continuing to meet the site’s conservation objectives.
Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the puffin feature of the Forth Islands SPA as a result of displacement from the Array in combination with other developments.
It is noted that the Scottish Ministers were unable to conclude no AEOI for the puffin feature of Forth Islands SPA from the Green Volt Offshore Wind Farm in-combination with other North Sea wind farms (Scottish Government, 2024). However, that conclusion was based on Green Volt’s PVA result indicating a CPS of 0.372 and CGR of 0.973, which represents a level of impact substantially higher than the predicted PVA impact demonstrated in this RIAA in Table 5.88 Open ▸ (CGR ranging from 0.999 to 0.996). Therefore, the conclusion drawn by the Scottish Ministers for the puffin feature of the Forth Islands in the Green Volt Offshore Wind Farm Appropriate Assessment (Appendix B of Scottish Government, 2024) does not affect the conclusion of no potential for AEOI drawn for this RIAA.

Gannet

The source information regarding gannet disturbance mortality from other relevant projects is given in Table 5.89 Open ▸ .

Table 5.89: Gannet Displacement Mortalities Apportioned to the Forth Islands SPA from Other Relevant Projects

*Apportioned impacts only presented on an annual basis in source document.

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.90 Open ▸ .

Table 5.90: Gannet Displacement Mortalities Apportioned to the Forth Islands SPA In-Combination Totals

With a population of 150,518 breeding adults (Burnell et al., 2023), 121.9 to 457.5 additional mortalities represents a 0.081 to 0.304 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.91 Open ▸ . Full details are available in appendix 3B.

Table 5.91: Summary of PVA Results for In-Combination Displacement Impacts on Gannet at the Forth Islands SPA

The gannet population of the Forth Islands SPA increased significantly from its citation level of 43,200 breeding adults to counts of 150,518 breeding adults from the census conducted in 2014 as part of the gannet census (Burnell et al., 2023). However, that data pre-dates the HPAI outbreak. Counts conducted in 2023 estimate the gannet population of Bass Rock to be 51,844 AOS (103,688 breeding adults), representing a significant decline (Harris et al., 2023). Whilst this decline is dramatic, the population remains above its citation level, and the available evidence suggests that the population is already showing signs of recovery (Tyndall et al., 2024). It is evident from the prior growth that there are ample suitable nesting sites on Bass Rock, and sufficient prey within foraging range to support a larger population. Therefore, it would be expected that the population will be able to rapidly recover.
The CGR ranges from 0.996 to 0.999. The CPS ranges from 0.879 to 0.966. Given the significant growth of the gannet population prior to the HPAI outbreak, and given recent evidence that the population size is growing again, this level of impact is not of a magnitude that is expected to adversely affect the population from meeting its conservation objectives.
Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the gannet feature of the Forth Islands SPA as a result of displacement from the Array in combination with other developments.

Breeding Seabird Assemblage

Of the components of the breeding assemblage, a potential LSE2 was identified for kittiwake, puffin and gannet. For each of those species, an assessment of the impact of displacement from the Array in-combination with other developments is provided above. It is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the gannet feature nor to the puffin feature. Kittiwake is not a feature of the site in its own right and is only included as a component of the assemblage. It was concluded that there is a potential for an adverse effect on the population size of the kittiwake feature under the High approach to assessment.
However, whilst, under the most precautionary approach to assessment, there might be a negative effect on the kittiwake population, the magnitude of that effect is small.Under the high approach to assessment including Berwick Bank, the CPS is 0.853, which indicates a population size 14.7% smaller than the counterfactual. Whilst such a decline may be distinguishable from natural variation, it is not considered a sufficiently large effect that it could be said to adversely affect the probability of kittiwake being maintained as a viable component of the seabird assemblage. Even if slightly lower in abundance, kittiwake would still be present as a functional breeding component of the site. Furthermore, as kittiwake is the only species being significantly impacted, the impact on the overall seabird assemblage size would be negligible, and not of a magnitude that would be detectable compared to natural variation, when considering the amount of variation that could arise across all component species (as noted above, both gannet and puffin have shown substantial population growth compared to their citation abundances). It should also be reiterated that the displacement and mortality rates applied under the “High” approach to assessment are not considered compatible with the best available science (see section 5.2.2). Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the Forth Islands SPA.

Fowlsheugh SPA

Kittiwake

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.92 Open ▸ .

Table 5.92: Kittiwake Displacement Mortalities Apportioned to the Fowlsheugh SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.93 Open ▸ .

Table 5.93: Kittiwake Displacement Mortalities Apportioned to the Fowlsheugh SPA In-Combination Totals

With a population of 28,078 breeding adults (Burnell et al, 2023), 17.1 to 83.2 additional mortalities represents a 0.061 to 0.296 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.94 Open ▸ . Full details are available in appendix 3B.

Table 5.94: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the Fowlsheugh SPA

The kittiwake population of the Fowlsheugh SPA has decreased between its citation level of 73,300 breeding adults and Seabird Census counts of 28,078 breeding adults (Burnell et al., 2023). However, more recent counts, that were conducted following the HPAI outbreak, indicate the population may be increasing again, with 15,443 AON (30,966 breeding adults) recorded in 2023 (Tremlett et al., 2024).
Under the “low” approach, the median CGR is 0.999 (whether including or excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines no more than 0.1%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.958 to 0.974. Overall, under this approach, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the kittiwake population compared to the counterfactual scenario.
However, under the “high” approach, the median CGR is 0.997 (including Berwick Bank Offshore Wind Farm) to 0.998 (excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines by 0.2% to 0.3% compared to the counterfactual. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.882 to 0.925. This level of impact is small, but considered of sufficient magnitude to be distinguishable from natural fluctuations. Given that the kittiwake population of the Fowlsheugh SPA has decreased significantly from its citation level, the magnitude of impact is sufficient to create an impact that could be said to have an adverse effect on the population. Therefore, it is concluded that there is a potential AEOI to the kittiwake feature of the Fowlsheugh SPA as a result of displacement impacts from the Array in-combination with other developments.

Razorbill (seabird assemblage component only)

The source information regarding razorbill disturbance mortality from other relevant projects is given in Table 5.95 Open ▸ .

Table 5.95: Razorbill Displacement Mortalities Apportioned to the Fowlsheugh SPA from Other Relevant Projects

*Apportioned impacts only presented on an annual basis in source document.

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.96 Open ▸ .

Table 5.96: Razorbill Displacement Mortalities Apportioned to the Fowlsheugh SPA In-Combination Totals

With a population of 18,844 breeding adults (Burnell et al, 2023), 20.2 to 130.6 additional mortalities represents a 0.107 to 0.693 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.97 Open ▸ . Full details are available in appendix 3B.

Table 5.97: Summary of PVA Results for In-Combination Displacement Impacts on Razorbill at the Fowlsheugh SPA

The razorbill population of the Fowlsheugh SPA has increased between its citation level of 5,800 breeding adults and recent counts of 18,844 breeding adults (Burnell et al., 2023).
Whilst the PVA results indicate a significant population decline from the current level, given the positive growth observed to date, that outcome is considered implausible for this site and so the assessment relies on the CPS and CGR.
Under the “low” approach, the median CGR is 0.998 (including Berwick Bank Offshore Wind Farm) to 0.999 (excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines 0.1% to 0.2%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.946 to 0.956. Overall, under this approach, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the razorbill population compared to the counterfactual scenario.
However, under the “high” approach, the median CGR is 0.992 (including Berwick Bank Offshore Wind Farm) to 0.993 (excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines by 0.7% to 0.8% compared to the counterfactual. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.746 to 0.785. This level of impact is moderate, and despite the population growth observed to date, the magnitude of impact is sufficient to create an impact that could be said to have an adverse effect on the population. However, razorbill is not a qualifying feature it its own right, and instead only qualifies as a named component of the breeding seabird assemblage.

Breeding Seabird Assemblage

Of the components of the seabird assemblage at Fowlsheugh SPA, a potential LSE2 was identified only for kittiwake and razorbill. Assessments of the impact of displacement from the Array in-combination with other developments for those components are presented above.
Under the low approach to assessment, the impact for both species is deemed to be negligible, and so it can be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI of the seabird assemblage feature.
However, under the high approach to assessment, it was found that the population of both kittiwake and razorbill components could be expected to decline significantly. Given this impact on two of the five named components of the assemblage, it is concluded that, under the high approach to assessment, there is a potential for an AEOI on the seabird assemblage feature of the Fowlsheugh SPA.

Hermaness, Saxa Vord and Valla Field SPA

Gannet

The source information regarding gannet disturbance mortality from other relevant projects is given in Table 5.98 Open ▸ .

Table 5.98: Gannet Displacement Mortalities Apportioned to the Hermaness, Saxa Vord and Valla Field SPA from Other Relevant Projects

*Apportioned impacts only presented on an annual basis in source document.

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.99 Open ▸ .

Table 5.99: Gannet Displacement Mortalities Apportioned to the Hermaness, Saxa Vord and Valla Field SPA In-Combination Totals

With a population of 59,124 breeding adults (Burnell et al, 2023), 14.9 to 45.9 additional mortalities represents a 0.025 to 0.078 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.100 Open ▸ . Full details are available in appendix 3B.

Table 5.100: Summary of PVA Results for In-Combination Displacement Impacts on Gannet at the Hermaness, Saxa Vord and Valla Field SPA

The gannet population of the Hermaness, Saxa Vord and Valla Field SPA has increased between its citation level of 32,800 breeding adults to recent counts of 59,124 breeding adults (Burnell et al., 2023).
The CGR ranges from 0.999 to 1.000. The CPS ranges from 0.968 to 0.990. When considering the growth of the gannet population within the Hermaness, Saxa Vord and Valla Field SPA, this level of impact is not of a magnitude that is expected to adversely affect the population from meeting its conservation objectives.
Therefore, it is concluded that there is no potential for an AEOI to the gannet feature of the Hermaness, Saxa Vord and Valla Field SPA as a result of displacement from the Array in combination with other developments.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, gannet was the only species for which a potential LSE2 was identified. As detailed above, there is expected to be no AEOI on the gannet feature. Therefore, it can also be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the Hermaness, Saxa Vord and Valla Field SPA as a result of displacement from the Array in combination with other developments.

North Caithness Cliffs SPA

Kittiwake (seabird assemblage component only)

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.101 Open ▸ .

Table 5.101: Kittiwake Displacement Mortalities Apportioned to the North Caithness Cliffs SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.102 Open ▸ .

Table 5.102: Kittiwake Displacement Mortalities Apportioned to the North Caithness Cliffs SPA In-Combination Totals

With a population of 11,142 breeding adults (Burnell et al, 2023), 9.0 to 25.7 additional mortalities represents a 0.080 to 0.231 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.103 Open ▸ . Full details are available in appendix 3B.

Table 5.103: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the North Caithness Cliffs SPA

The kittiwake population of the North Caithness Cliffs SPA has decreased between its citation level of 26,200 breeding adults to recent counts of 11,142 breeding adults (Burnell et al., 2023).
Under the “low” approach, the median CGR is 0.999 (whether including or excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines no more than 0.1%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.961 to 0.906. Overall, under this approach, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the kittiwake population compared to the counterfactual scenario.
However, under the “high” approach, the median CGR is 0.997 (including Berwick Bank Offshore Wind Farm) to 0.998 (excluding Berwick Bank Offshore Wind Farm) which indicates the population growth rate declines by 0.2% to 0.3% compared to the counterfactual. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.906 to 0.919. This level of impact is small, but considered of sufficient magnitude to be distinguishable from natural fluctuations. Given that the kittiwake population of the North Caithness Cliffs SPA has decreased significantly from its citation level, the magnitude of impact is sufficient to create an impact that could be said to have an adverse effect on the population. However, kittiwake is not a qualifying feature it its own right, and instead only qualifies as a named component of the breeding seabird assemblage.
Recent surveys indicate that kittiwake at the North Caithness Cliffs SPA have not been harmed by HPAI, and indeed the population appears to be growing. Considering matched sites within the North Caithness Cliffs SPA, the population of kittiwakes has increased from 5,299 AON in the Seabird Count data collection period to 7,481 AON in 2023, a 40% increase (Tremlett et al., 2024). (Note that not all sites were surveyed in 2023, and therefore these figures do not represent the full SPA population).

Breeding Seabird Assemblage

Of the components of the breeding seabird assemblage at the North Caithness Cliffs SPA, a potential LSE2 was identified only for kittiwake, for which an assessment has been provided above.
Under the low approach to assessment, the impact of displacement from the Array in-combination with other developments was found to make no material impact, and therefore it can be concluded, beyond reasonable scientific doubt, there is no AEOI to the seabird assemblage feature of the North Caithness Cliffs SPA.
Under the high approach to assessment, it was concluded that the kittiwake population might be adversely affected. However, whilst there might be a negative effect on the kittiwake population, the magnitude of that effect is small. It is not considered a sufficiently large effect that it could be said to adversely affect the probability of kittiwake being maintained as a viable component of the seabird assemblage. Furthermore, as kittiwake is the only species being significantly impacted, it could not be said to adversely affect the probability of the total seabird assemblage being maintained. Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the North Caithness Cliffs SPA as a result of displacement impacts from the Array in-combination with other developments.

Noss SPA

Gannet

The source information regarding gannet disturbance mortality from other relevant projects is given in Table 5.104 Open ▸ .

Table 5.104: Gannet Displacement Mortalities Apportioned to the Noss SPA from Other Relevant Projects

*Apportioned impacts only presented on an annual basis in source document.

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.105 Open ▸ .

Table 5.105: Gannet Displacement Mortalities Apportioned to the Noss SPA In-Combination Totals

With a population of 27,530 breeding adults (Burnell et al, 2023), 6.7 to 21.7 additional mortalities represents a 0.025 to 0.079 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.106 Open ▸ . Full details are available in appendix 3B.

Table 5.106: Summary of PVA Results for In-Combination Displacement Impacts on Gannet at the Noss SPA

The gannet population of the Noss SPA has increased from its citation level of 13,720 breeding adults to recent counts of 27,530 breeding adults (Burnell et al., 2023).
The CGR ranges from 0.999 to 1.000. The CPS ranges from 0.967 to 0.990. When considering the growth of the gannet population within the Noss SPA, this level of impact is not of a magnitude that is expected to adversely affect the population from meeting its conservation objectives.
Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the gannet feature of the Noss SPA as a result of displacement from the Array in combination with other developments.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, gannet was the only species for which a potential LSE2 was identified. As detailed above, there is expected to be no AEOI on the gannet feature. Therefore, it can also be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the Noss SPA as a result of displacement from the Array in combination with other developments.

St Abb’s Head to Fast Castle SPA

Kittiwake (seabird assemblage component only)

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.107 Open ▸ .

Table 5.107: Kittiwake Displacement Mortalities Apportioned to the St Abb’s Head to Fast Castle SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.108 Open ▸ .

Table 5.108: Kittiwake Displacement Mortalities Apportioned to the St Abb’s Head to Fast Castle SPA In-Combination Totals

With a population of 10,300 breeding adults (Burnell et al, 2023), 5.3 to 104.3 additional mortalities represents a 0.052 to 1.013 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.109 Open ▸ . Full details are available in appendix 3B.

Table 5.109: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the St Abb’s Head to Fast Castle SPA

The kittiwake population of the St Abb’s Head to Fast Castle SPA has decreased between its citation level of 42,340 breeding adults and recent counts of 10,300 breeding adults (Burnell et al., 2023).
If Berwick Bank Offshore Wind Farm is excluded, the median CGR is 0.999 to 0.998 which indicates the population growth rate declines 0.1% to 0.2%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.979 to 0.937. Overall, under this scenario, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the kittiwake population compared to the counterfactual scenario.
However, if Berwick Bank Offshore Wind Farm is included, the median CGR is 0.996 (under the “low” approach) to 0.988 (under the “high” approach) which indicates the population growth rate declines by 0.4% to 1.2% compared to the counterfactual. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.865 to 0.648. This level of impact is small, but considered of sufficient magnitude to be distinguishable from natural fluctuations. Given that the kittiwake population of the St Abb’s Head to Fast Castle SPA has decreased significantly from its citation level, the magnitude of impact is sufficient to create an impact that could be said to have an adverse effect on the population.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, kittiwake was the only species for which a potential LSE2 was identified. An assessment of the impact on kittiwake is provided above.
If Berwick Bank Offshore Wind Farm is excluded it was found there will be no material impact to kittiwake, and therefore no potential impact on the seabird assemblage. However, if Berwick Bank Offshore Wind Farm is included, then it is likely that the kittiwake population will decline. Kittiwake were a significant portion of the assemblage at designation, consisting 21,170 pairs. As of the Seabirds Count census, this had declined to 5,150 pairs. It is concluded that the magnitude of decline if Berwick Bank Offshore Wind Farm is included is sufficient that it could adversely affect kittiwake being maintained as a viable component of the assemblage. It is also concluded that it could negatively affect the total size of the breeding seabird assemblage population.
Therefore, it is concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the St Abb’s Head to Fast Castle SPA if Berwick Bank Offshore Wind Farm is excluded, but there is a potential AEOI to the seabird assemblage feature of the St Abb’s Head to Fast Castle SPA from the in-combination displacement impact of the Array and other developments including Berwick Bank Offshore Wind Farm.

St Kilda SPA

Gannet

The source information regarding gannet disturbance mortality from other relevant projects is given in Table 5.110 Open ▸ .

Table 5.110: Gannet Displacement Mortalities Apportioned to the St Kilda SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.111 Open ▸ .

Table 5.111: Gannet Displacement Mortalities Apportioned to the St Kilda SPA In-Combination Totals

With a population of 120,580 breeding adults (Burnell et al, 2023), 0.4 to 1.4 additional mortalities represents a 0.000 to 0.001 percentage point increase in mortality rates. Therefore, it can be concluded, beyond reasonable scientific doubt, that there is no risk of an AEOI to the gannet feature of St Kilda SPA resulting from displacement impact from the Array in-combination with other developments.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, gannet was the only species for which a potential LSE2 was identified for displacement. As detailed above, there is expected to be no AEOI on the gannet feature. Therefore, it can also be concluded, beyond reasonable scientific doubt, that there is no potential for an AEOI to the seabird assemblage feature of the St Kilda SPA as a result of displacement from the Array in combination with other developments.

Troup, Pennan and Lion’s Head SPA

Kittiwake

The source information regarding kittiwake disturbance mortality from other relevant projects is given in Table 5.112 Open ▸ .

Table 5.112: Kittiwake Displacement Mortalities Apportioned to the Troup, Pennan and Lion’s Head SPA from Other Relevant Projects

From this information, the various approaches have been consolidated into a “low” and a “high” estimate for the total in-combination impact. This is presented in Table 5.113 Open ▸ .

Table 5.113: Kittiwake Displacement Mortalities Apportioned to the Troup, Pennan and Lion’s Head SPA In-Combination Totals

With a population of 21,232 breeding adults (Burnell et al, 2023), 12.1 to 42.3 additional mortalities represents a 0.057 to 0.199 percentage point increase in mortality rates. Therefore, PVA has been carried out both with and without Berwick Bank Offshore Wind Farm and for the high and low scenarios, to further assess the total in-combination impact.
The PVA results are summarised in Table 5.114 Open ▸ . Full details are available in appendix 3B.

Table 5.114: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the Troup, Pennan and Lion’s Head SPA

The kittiwake population of the Troup, Pennan and Lion’s Head SPA has decreased between its citation level of 63,200 breeding adults and recent counts of 21,232 breeding adults (Burnell et al., 2023).
The median CGR is 0.998 to 0.999 which indicates the population growth rate declines no more than 0.2%. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.918 to 0.976. Overall, under this approach, the impact of displacement from the Array in combination with other projects is predicted to make no material impact on the kittiwake population compared to the counterfactual scenario.
Therefore, it can be concluded, beyond reasonable scientific doubt, that there is no risk of an AEOI to the kittiwake feature of the Troup, Pennan and Lion’s Head SPA resulting from displacement impact from the Array in-combination with other developments.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, kittiwake was the only species for which a potential LSE2 was identified for displacement. As detailed above, there is expected to be no AEOI on the kittiwake feature. Therefore, it can also be concluded, beyond reasonable scientific doubt,that there is no potential for an AEOI to the seabird assemblage feature of the Troup, Pennan and Lion’s Head SPA as a result of displacement from the Array in combination with other developments.

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