Hermaness, Saxa Vord and Valla Field SPA

Gannet

The source information regarding gannet collision mortality from other relevant projects is given in Table 5.140 Open ▸ .

Table 5.140: Gannet Collision Mortalities Apportioned to the Hermaness, Saxa Vord and Valla Field SPA from Other Relevant Projects

Project(s)	Data Source	Approach	Adult Mortalities
Project(s)	Data Source	Approach	Pre-Breeding Season	Breeding Season	Post-Breeding	Annual Total
UK North Sea projects	SSE Renewables (2022)	Scoping	25.6	0.8	35.2	61.6
UK North Sea projects	SSE Renewables (2022)	Developer	25.5	0.6	34.9	61.0
Green Volt Offshore Wind Farm	Green Volt Offshore Wind Farm (2023)	N/A	1.2	6.4	0.1	7.7
West of Orkney Wind Farm	Offshore Wind Power Limited (2023)	Low	3.3	0.0	1.8	5.1
West of Orkney Wind Farm	Offshore Wind Power Limited (2023)	Mid	3.3	0.0	2.6	5.9
West of Orkney Wind Farm	Offshore Wind Power Limited (2023)	High	4.5	0.0	3.3	7.8
Pentland Floating Offshore Wind	Xodus Group Ltd (2022)	N/A	0.0	0.1	0.0	0.1
SEP & DEP	Equinor (2022)	Developer	0.0	0.0	0.3	0.3
Outer Dowsing	Outer Dowsing Offshore Wind (2023)	Developer	N/A	N/A	N/A	0.0*
Berwick Bank Offshore Wind Farm alone	SSE Renewables (2022)	Scoping	0.1	0.8	0.9	1.8
Berwick Bank Offshore Wind Farm alone	SSE Renewables (2022)	Developer	0.1	0.6	0.6	1.3

*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 5.141 Open ▸ .

Table 5.141: Gannet Collision Mortalities Apportioned to the Hermaness, Saxa Vord and Valla Field SPA In-Combination Totals

Project(s)	Adult Mortalities
	Pre-Breeding Season		Breeding Season		Post-Breeding Season		Annual Total
	Low	High	Low	High	Low	High	Low	High
UK North Sea projects	25.5	25.6	0.6	0.8	34.9	35.2	61.0	61.6
Green Volt Offshore Wind Farm	1.2	1.2	6.4	6.4	0.1	0.1	7.7	7.7
West of Orkney Wind Farm	3.3	4.5	0.0	0.0	1.8	3.3	5.1	7.8
Pentland Floating Offshore Wind	0.0	0.0	0.1	0.1	0.0	0.0	0.1	0.1
SEP & DEP	0.0	0.0	0.0	0.0	0.3	0.3	0.3	0.3
Outer Dowsing	N/A	N/A	N/A	N/A	N/A	N/A	0.0	0.0
Berwick Bank Offshore Wind Farm	0.1	0.1	0.6	0.8	0.6	0.9	1.3	1.8
Ossian	0.0	0.0	0.6	1.1	0.3	0.5	0.9	1.6
Total (Including Berwick Bank Offshore Wind Farm)	30.1	31.3	7.7	8.3	37.4	39.4	75.1	79.1
Total (Excluding Berwick Bank Offshore Wind Farm)	30.0	31.2	7.1	7.5	36.8	38.5	73.8	77.3

With a population of 59,124 breeding adults (Burnell et al., 2023), 73.8 to 79.1 additional mortalities represents a 0.125 to 0.134 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 5.142 Open ▸ . Full details are available in appendix 3B.

Table 5.142: Summary of PVA Results for In-Combination Collision Impacts on Gannet at the Hermaness, Saxa Vord and Valla Field SPA

Scenario	Approach	Adult Mortality	Citation Population (Breeding Adults)	Recent Population (Burnell et al., 2023) (Breeding Adults)	Median Unimpacted Population After 35 Years	Median Impacted Population After 35 Years	Median CGR	Median CPS
Including Berwick Bank Offshore Wind Farm	Low	75.1	32,800	59,124	79,619	75,454	0.999	0.948
Including Berwick Bank Offshore Wind Farm	High	79.1				75,102	0.998	0.945
Excluding Berwick Bank Offshore Wind Farm	Low	73.8				75,512	0.999	0.949
Excluding Berwick Bank Offshore Wind Farm	High	77.3				75,324	0.998	0.946

The gannet population of the Hermaness, Saxa Vord and Valla Field SPA has increased between its citation level of 32,800 breeding adults and recent counts of 59,124 breeding adults (Burnell et al., 2023).
The CGR ranges from 0.998 to 0.999. The CPS ranges from 0.945 to 0.949. 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. This is concluded due to both the impacted and unimpacted scenarios predicting the population to be be far greater than the citation population.
Therefore, there is no potential for an AEOI to the gannet feature of the Hermaness, Saxa Vord and Valla Field SPA as a result of collision 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 AEOI to the seabird assemblage feature of the Hermaness, Saxa Vord and Valla Field SPA as a result of collision from the Array in combination with other developments.

North Caithness Cliffs SPA

Kittiwake (seabird assemblage component only)

The source information regarding kittiwake collision mortality from other relevant projects is given in Table 5.143 Open ▸ .

Table 5.143: Kittiwake Collision Mortalities Apportioned to the North Caithness Cliffs SPA from Other Relevant Projects

Project(s)	Data Source	Approach	Adult Mortalities
Project(s)	Data Source	Approach	Pre-Breeding Season	Breeding Season	Post-Breeding	Annual Total
UK North Sea projects	SSE Renewables (2022)	Scoping	20.3	3.7	15.5	39.5
UK North Sea projects	SSE Renewables (2022)	Developer	19.7	3.7	14.4	37.8
Green Volt Offshore Wind Farm	Green Volt Offshore Wind Farm (2023)	N/A	0.1	0.1	0.1	0.3
West of Orkney Wind Farm	Offshore Wind Power Limited (2023)	Low	0.8	3.6	0.6	5.0
West of Orkney Wind Farm	Offshore Wind Power Limited (2023)	Mid	0.9	4.2	0.7	5.8
West of Orkney Wind Farm	Offshore Wind Power Limited (2023)	High	0.9	4.9	0.7	6.5
Pentland Floating Offshore Wind	Xodus Group Ltd (2022)	N/A	N/A	5.0	0.0	5.0
Outer Dowsing	Outer Dowsing Offshore Wind (2023)	Developer	N/A	N/A	N/A	1.2*
Berwick Bank Offshore Wind Farm alone	SSE Renewables (2022)	Scoping	3.6	0.0	2.7	6.3
Berwick Bank Offshore Wind Farm alone	SSE Renewables (2022)	Developer	2.9	0.0	1.6	4.5

*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 5.144 Open ▸ .

Table 5.144: Kittiwake Collision Mortalities Apportioned to the North Caithness Cliffs SPA In-Combination Totals

Project(s)	Adult Mortalities
	Pre-Breeding Season		Breeding Season		Post-Breeding Season		Annual Total
	Low	High	Low	High	Low	High	Low	High
UK North Sea projects	19.7	20.3	3.7	3.7	14.4	15.5	37.8	39.5
Green Volt Offshore Wind Farm	0.1	0.1	0.1	0.1	0.1	0.1	0.3	0.3
West of Orkney Wind Farm	0.8	0.9	3.6	4.9	0.6	0.7	5.0	6.5
Pentland Floating Offshore Wind	N/A	N/A	5.0	5.0	0.0	0.0	5.0	5.0
Outer Dowsing	N/A	N/A	N/A	N/A	N/A	N/A	1.2	1.2
Berwick Bank Offshore Wind Farm	2.9	3.6	0.0	0.0	1.6	2.7	4.5	6.3
Ossian	0.0	0.1	0.0	0.0	0.0	0.1	0.0	0.2
Total (Including Berwick Bank Offshore Wind Farm)	20.6	21.5	12.5	13.7	15.1	16.4	49.4	52.8
Total (Excluding Berwick Bank Offshore Wind Farm)	17.7	17.9	12.5	13.7	13.5	13.7	44.9	46.5

With a population of 11,142 breeding adults (Burnell et al., 2023), 44.9 to 52.8 additional mortalities represents a 0.403 to 0.474 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 5.145 Open ▸ . Full details are available in appendix 3B.

Table 5.145: Summary of PVA Results for In-Combination Displacement Impacts on Kittiwake at the North Caithness Cliffs SPA

Scenario	Approach	Adult Mortality	Citation Population (Breeding Adults)	Recent Population (Burnell et al., 2023) (Breeding Adults)	Median Unimpacted Population After 35 Years	Median Impacted Population After 35 Years	Median CGR	Median CPS
Including Berwick Bank Offshore Wind Farm	Low	49.4	26,200	11,142	10,778	8,704	0.995	0.827
Including Berwick Bank Offshore Wind Farm	High	52.8				8,583	0.994	0.816
Excluding Berwick Bank Offshore Wind Farm	Low	44.9				8,849	0.995	0.842
Excluding Berwick Bank Offshore Wind Farm	High	46.5				8,805	0.995	0.836

The kittiwake population of the North Caithness Cliffs SPA has decreased between its citation level of 26,200 breeding adults and recent counts of 11,142 breeding adults (Burnell et al., 2023).
The median CGR is 0.994 to 0.995 (under all scenarios and approaches) which indicates the population growth rate declines by 0.5% to 0.6% compared to the counterfactual. After 35 years (the expected lifespan of the Array), the CPS ranges from 0.816 to 0.842. 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.

Breeding Seabird Assemblage

Of the components of the seabird assemblage, kittiwake was the only species for which a potential LSE2 was identified for collision risk. As detailed above, there is expected to be a significant impact on the kittiwake population. The kittiwake population at citation was significantly higher than the current population (Burnell et al., 2023). Whilst the magnitude of the impact would not be deemed sufficient to risk entirely losing kittiwake as a viable component of the assemblage, the decline is sufficient to adversely affect the total population size of the overall assemblage.
Therefore, it is concluded that there is a potential AEOI to the seabird assemblage feature of the North Caithness Cliffs SPA as a result of the impact of collision from the Array in-combination with other developments.

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