4 Conclusions

Below, we summarise the worst case, in terms of reduction in population growth rate and median population size for each species for the expected life-span of the project (25 years). In all cases, modelling of Scoping Approach mortality estimates resulted in greatest effects for project alone and in-combination. It is important to note that density dependent effects on growth rate are not included in these models.
For gannet, project alone impacts were greatest at Forth Islands SPA for Scoping Approach B at the end of 35 years of impact (2062) resulting in a 4.3% and 0.1% reduction in population growth rate and median population size, respectively. With regards incombination impacts, the North Sea consented Scoping B was the worst case for the Flamborough and Filey Coast SPA resulting in a 39% and 14% reduction in population growth rate and median population size, respectively
For guillemot, project alone impacts were greatest at St Abb’s Head to Fast Castle SPA for Scoping Approach B at the end of 35 years of impact (2062) resulting in a 33% and 11% reduction in population growth rate and median population size, respectively. With regards incombination impacts on this SPA, the North Sea consented Scoping B was the worst case for resulting in a 38% and 13% reduction in population growth rate and median population size, respectively. The incombination totals compares with the equivalent Developer Approach scenario of 8.6% and 0.02% reduction in population growth rate and median population size, respectively.
For herring gull, project alone impacts were greatest at St Abb’s Head to Fast Castle SPA for Scoping Approach at the end of 35 years of impact (2062) resulting in a 2.9% and 0.01% reduction in population growth rate and median population size, respectively. With regards incombination impacts on this SPA, the North Sea consented Scoping was the worst case resulting in a 5.3% and 0.01% reduction in population growth rate and median population size, respectively.
For kittiwake, project alone impacts were greatest at St Abb’s Head to Fast Castle SPA for Scoping Approach B at the end of 35 years of impact (2062) resulting in a 62.5% and 2.7% reduction in population growth rate and median population size, respectively. With regards incombination impacts on this SPA, the North Sea consented Scoping B was the worst case for resulting in a 65.9% and 29.9% reduction in population growth rate and median population size, respectively. The incombination totals compares with the equivalent Developer Approach scenario of 52.1% and 2% reduction in population growth rate and median population size, respectively.
For lesser black-back gull, project alone impacts were greatest at Forth Islands SPA for Scoping Approach at the end of 35 years of impact (2062) resulting in a 1.8% and 0.01% reduction in population growth rate and median population size, respectively.
For puffin, project alone impacts were greatest at Forth Islands SPA for Scoping Approach B at the end of 35 years of impact (2062) resulting in a 1.4% reduction in population growth rate but no change in median population size, respectively. With regards incombination impacts on this SPA, the North Sea consented Scoping B was the worst case for resulting in a 12% and 0.04% reduction in population growth rate and median population size, respectively.
For razorbill, project alone impacts were greatest at St Abb’s Head to Fast Castle SPA for Scoping Approach B at the end of 35 years of impact (2062) resulting in a 14.1% reduction in population growth rate and 0.04% reduction in median population size. With regards incombination impacts on this SPA, the North Sea consented Scoping B was the worst case for resulting in a 20.6% and 0.06% reduction in population growth rate and median population size, respectively.

5 References

Caswell, H. (2000). Matrix population models (Vol. 1). Sunderland: Sinauer.

Centre for Ecology and Hydrology (CEH). (2018). Isle of May breeding season summaries. URL: https://www.ceh.ac.uk/isle-may-breeding-season-summaries. Accessed 20 March 2021.

Chabrzyk, G. and Coulson, J.C. (1976). Survival and recruitment in the herring gull Larus argentatus. Journal of Animal Ecology, 45, pp.187–203.

Cook, A.S.C.P and Robinson, R.A. (2010). How Representative is the Current Monitoring of Breeding Seabirds in the UK? BTO Research Report No. 573. British Trust for Ornithology.

Deakin, Z., Hamer, KC., Sherley, RB., Bearhop, S., Bodey, TW., Clark, BL., Grecian, WJ., Gummery, M., Lane, J., Morgan, G., Morgan, L., Phillips, RA., Wakefield, ED. and Votier, SC. (2019). Sex differences in migration and demography of a wide-ranging seabird, the northern gannet. Marine Ecology Progress Series, 622, pp.191-201. ISSN 0171-8630.

Frederiksen, M., Wanless, S., Harris, M.P., Rothery, P. and Wilson, L.J. (2004). The role of industrial fisheries and oceanographic change in the decline of North Sea black-legged kittiwakes. Journal of Applied Ecology, 41, pp.1129–1139.

Harris, M.P. (1970). Rates and causes of increases of some British gull populations. Bird Study, 17, pp.325–335.

Harris, M.P., Frederiksen, M. and Wanless, S. (2007). Within- and between-year variation in the juvenile survival of common guillemots Uria aalge. Ibis, 149, pp.472–481.

Horswill, C. and Robinson R.A. (2015). Review of seabird demographic rates and density dependence. JNCC Report No. 552. Joint Nature Conservation Committee, Peterborough

Jitlal, M., Burthe, S., Freeman S. and Daunt, F. (2017). Testing and Validating Metrics of Change Produced by Population Viability Analysis (PVA). Scottish Marine and Freshwater Science, 8(23), pp.210. DOI: 10.7489/2018-1.

Lahoz-Monfort, J.J., Morgan, B.J.T., Harris, M.P., Wanless, S. and Freeman, S.N. (2011). A capture-recapture model for exploring multi-species synchrony in survival. Methods in Ecology and Evolution, 2, pp.116–124.

Marine Scotland – Licensing Operations Team (MS-LOT). (2022). Marine Scotland Licensing Operations Team: Scoping Opinion for Berwick Bank Offshore Wind Farm. Marine Scotland. pp.45.

Mobbs, D., Searle, K., Daunt, F. and Butler, A. (2020). A Population Viability Analysis Modelling Tool for Seabird Species: Guide for using the PVA tool (v2.0) user interface. Available at: https://github.com/naturalengland/Seabird_PVA_Tool/blob/master/Documentation/PVA_Tool_UI_Guidance.pdf. Accessed: November 2021.

Oro, D., Furness, R.W. (2002). Influences of food availability and predation on survival of Kittiwakes. Ecology, 83(9), pp.2516 – 2528.

Searle, K., Mobbs, D., Daunt, F., and Butler, A. (2019). A Population Viability Analysis Modelling Tool for Seabird Species. Centre for Ecology and Hydrology report for Natural England. Natural England Commissioned Report NECR274. pp.23

SMP. (2022). Seabird Monitoring Programme Online Database. URL: https://app.bto.org/seabirds/public/index.jsp Accessed 20 January 2022.

Snow, D.W. and Perrins, C.M. (1998). The birds of the western Palearctic, Concise edition. Oxford University Press.

Wanless, S., Frederiksen, M., Harris, M.P. and Freeman, S.N. (2006). Survival of Gannets Morus bassanus in Britain and Ireland, 1959–2002, Bird Study, 53(1), pp.79-85, DOI: 10.1080/00063650609461419.

Wanless, S., Harris, M.P., Calladine, J. and Rothery, P. (1996). Modelling responses of herring gull and lesser black backed gull populations to reduction of reproductive output: Implications for control measures. Journal of Applied Ecology, 33, pp.1420–1432

Woodward, I., Thaxter, C. B., Owen, E. and Cook, A.S.C.P. (2019). Desk-based revision of seabird foraging ranges used for HRA screening. BTO research report number 724.

ANNEX A Breeding seaon apportioned mortality

ANNEX B Non-breeding season apportioned mortality

ANNEX C Threshold application for population viability analysis

ANNEX D Incombination mortality and scenarios

ANNEX E Summary of approach and collation of incombination totals

ANNEX F Asymptotic age distributions

Last part

Next part

Tables ▼