5. Conclusion

  1. Apportioning provides a means of determining the proportions of birds and their colonies of origin within the Development area. The weightings/proportions in Section 4 were used to apportion breeding season and non-breeding season species specific estimated mortalities of birds (from collision and/or displacement) to their likely colony of origin (i.e., SPA or non-designated colony) (Annex D).
  2. For kittiwake, apportioning using the MSS method predicted that the greatest proportion of birds at the Proposed Development area are from the St Abb’s Head to Fast Castle SPA (52.2%). A further 17.2% of birds are apportioned to Fowlsheugh SPA. During the non-breeding season, proportions of adults are highest from East Caithness Cliffs SPA and Flamborough and Filey Coast SPA during the autumn (5.8% and 5.4% respectively) and spring migrations (7.7% and 7.2% respectively).
  3. For herring gull, the greatest proportion of birds at the Proposed Development Array area are likely from the Forth Islands SPA in both the breeding and non-breeding seasons (same apportioning method; 58.8%). Mortality estimates at the colonies during the non-breeding season were adjusted for the influx of winter birds (Annex D).  
  4. For lesser black backed gull, 52.5% of birds at the Proposed Development Array area are likely from the Forth Islands SPA during the breeding season. During the non-breeding season, this proportion is significantly reduced for this SPA at 4.1% adults during winter; however, there is no predicted non-breeding season mortality for this species (Annex D). Breeding season proportions for the Farne Islands SPA and Coquet Island SPA were 13.6% and 0.2%, respectively.
  5. For guillemot, the majority of birds at the Proposed Development area during the breeding season likely originate from the St Abbs Head to Fast Castle SPA (41.6%) and Fowlsheugh SPA (35.9%). A further 10.9% of birds are apportioned to the Forth Islands SPA. During the non-breeding season, the highest proportion of birds in the regional population were associated with St Abb’s Head to Fast Castle, Fowlsheugh and Farne Islands SPAs at 33%, 22.3% and 20.6% respectively.
  6. For razorbill, apportioned birds during the breeding season are almost equal between Fowlsheugh SPA (29.2%) and Forth Islands SPA (26.5%). A further 23.1% of birds are apportioned to St Abb’s Head to Fast Castle SPA during the breeding season. Non-breeding season proportions were highest for the East Caithness Cliffs SPA and the Flamborough and Filey Coast SPA during autumn and spring migrations (4.2% and 3.4%, respectively) and winter (3.4% and 2.7%, respectively).
  7. For puffin, breeding season birds at the Proposed Development area are primarily apportioned between Forth Islands SPA (50%), Farne Islands SPA (38.2%) and Coquet Island SPA (10.6%).  Non-breeding season impacts on puffin were not assessed.
  8. For gannet, 97.1% of breeding season birds are apportioned to the Forth Islands SPA. A further 18% and 33% of non-breeding season adult birds (autumn and spring migration, respectively) are attributed to the Forth Islands SPA.

6. Summary

  1. Apportioning provides a means of determining the proportions of birds and their colonies of origin within the Proposed Development area. Furthermore, the results from apportioning allow the impacts to be allocated across each of the relevant Special Protected Areas (SPAs). Potential impacts from collision and displacement are presented in the Ornithology Technical Appendices 11.3 and 11.4, respectively and the apportioned impacts by age class are provided in Annex D.  
  2. Apportioning has been undertaken for the following species:
  • Kittiwake    Rissa tridactyla
  • Herring gull     Larus argentatus
  • Lesser black backed gull  Larus fuscus
  • Guillemot     Uria aalge
  • Razorbill    Alca torda
  • Puffin      Fratercula arctica
  • Gannet     Morus bassanus
    1. In the breeding season, apportioning to breeding colonies at SPAs and non-designated colonies within “foraging range” of the proposed Berwick Bank development has been undertaken using:
  • NatureScot’s interim guidance apportioning method (NatureScot, 2018); and
  • Marine Scotland Science (MSS) apportioning method using Wakefield et al. (2017; 2019) and implemented through the MS Apportioning Tool.
    1. Following the advice of NatureScot and Marine Scotland Science given through the Ornithology RoadMap process, foraging ranges were defined as the mean max foraging range + 1 SD from Woodward et al. (2019) for the NatureScot approach. The MSS method uses the maximum observed foraging range from GPS data and adds a 10% buffer to account for potentially unobserved foraging trips. Consequently, the lists of SPAs with connectivity derived from the two methods are not comparable.
    2. In the non-breeding season, for all species except guillemot and herring gull, the information from Furness (2015) on Biologically Defined Minimum Population Scales (BDMPS) has been used, this included using a methodology for gannet that took account of seasonal migrations. For guillemot and herring gull, non-breeding season estimates are apportioned based on breeding season population sizes. For herring gull, a correction factor was applied to account for the influx of birds from overseas into the regional population during the non-breeding season.
    3. For kittiwake, apportioning using the MSS method predicted that the greatest proportion of birds at the Proposed Development area are from the St Abb’s Head to Fast Castle SPA (52.2%). A further 17.2% of birds are apportioned to Fowlsheugh SPA. During the non-breeding season, proportions of adults are highest from East Caithness Cliffs SPA and Flamborough and Filey Coast SPA during the autumn (5.8% and 5.4% respectively) and spring migrations (7.7% and 7.2% respectively).
    4. For herring gull, the greatest proportion of birds at the Proposed Development area are likely from the Forth Islands SPA in both the breeding and non-breeding seasons (same apportioning method; 58.8%). Mortality estimates at the colonies during the non-breeding season were adjusted for the influx of winter birds. 
    5. For lesser black backed gull, 52.5% of birds at the Proposed Development Array area are likely from the Forth Islands SPA during the breeding season. During the non-breeding season, this proportion is significantly reduced for this SPA at 4.1% adults during winter, however there is no non-breeding season mortality for this species (Annex D). Breeding season proportions for the Farne Islands SPA and Coquet Island SPA were 13.6% and 0.2%, respectively.
    6. For guillemot, using the MSS method, the majority of birds at the Proposed Development area during the breeding season likely originate from the St Abbs Head to Fast Castle SPA (41.6%) and Fowlsheugh SPA (35.9%). A further 10.9% of birds are apportioned to the Forth Islands SPA. During the non-breeding season, the highest proportion of birds in the regional population were associated with St Abb’s Head to Fast Castle, Fowlsheugh and Farne Islands SPAs at 33%, 22.3% and 20.6% respectively.
    7. For razorbill, based on the MSS method, apportioned birds during the breeding season are almost equal between Fowlsheugh SPA (29.2%) and Forth Islands SPA (26.5%). A further 23.1% of birds are apportioned to St Abb’s Head to Fast Castle SPA during the breeding season. Non-breeding season proportions were highest for the East Caithness Cliffs SPA and the Flamborough and Filey Coast SPA during autumn and spring migrations (4.2% and 3.4%, respectively) and winter (3.4% and 2.7%, respectively).
    8. For puffin, breeding season birds at the Proposed Development area are primarily apportioned between Forth Islands SPA (50%), Farne Islands SPA (38.2%) and Coquet Island SPA (10.6%). Non-breeding season impacts on puffin were not assessed.
    9. For gannet, 97.1% of breeding season birds are apportioned to the Forth Islands SPA. A further 18% and 33% of non-breeding season adult birds (autumn and spring migration, respectively) are attributed to the Forth Islands SPA.

7. References

Buckingham, L., Bogdanova, M.I., Green, J.A., Dunn, R.E., Wanless, S., Bennett, S., Bevan, R.M., Call, A., Canham, M., Corse, C.J. and Harris, M.P., 2022. Interspecific variation in non-breeding aggregation: a multi-colony tracking study of two sympatric seabirds. Marine Ecology Progress Series, 684, pp.181-197. https://www.int-res.com/articles/meps_oa/m684p181.pdf

Butler, A., Carroll, M., Searle, K., Bolton, M., Waggitt, J., Evans, P., Rehfisch, M., Goddard, B., et al. (2020). Attributing seabirds at sea to appropriate breeding colonies. Scottish Marine and Freshwater Science 11(8). Marine Scotland Science.

Forrester, R.W., Andrews, I.J., Mcinerny, C.J., Murray, R.D., Mcgowan, R.Y., Zonfrillo, B., Betts, M.W., Jardine, D.C. and Grundy, D.S. (2007). The Birds of Scotland. Scottish Ornithologists’ Club, Aberlady.

Furness, R.W. (2015). Non-breeding season populations of seabirds in UK waters: Population sizes for Biologically Defined Minimum Population Scales (BDMPS). Natural England Commissioned Reports, No.164.

Harris, M. P., Heubeck, M., Shaw, D. N. and Okill, J. D. (2006). Dramatic changes in the return date of Guillemots Uria aalge to colonies in Shetland, 1962–2005. Bird Study, 53, 247-252.

McArthur Green (2015). Appendix 3 Apportioning of the Flamborough Head and Filet Coast pSPA gannet population among North Sea Offshore Windfarms. East Anglia THREE Information for Habitats Regulations Assessment. Document Reference – 5.4 (3). Report for Vattenfall and Scottish Power Renewables. 13pp.

NatureScot. (2018). Interim Guidance on apportioning impacts from marine renewable developments to breeding seabird populations in SPAs. NatureScot. [Online]. https://www.nature.scot/doc/interim-guidance-apportioning-impacts-marine-renewable-developments-breeding-seabird-populations. Access 27/01/2022.

NatureScot. (2020). Seasonal periods for birds in the Scottish marine environment. Short Guidance Note Version 2. NatureScot.

Seagreen (2019). Ornithology Habitats Regulation Appraisal. May 2019 Addendum relating to the Optimised Seagreen Alpha and Seagreen Bravo Offshore Wind Farm Applications submitted September 2018. 134pp. [Online]. https://www.seagreenwindenergy.com/may-2019-addendum. Access 27/01/2022.

SSE Renewables (2021). Berwick Bank Wind Farm Offshore HRA Screening Report. Available at: lse-screening-report (berwickbank-eia.com)

Wakefield, E.D., Owen, E., Baer, J., Carroll, M.J., Daunt, F., Dodd, S.G., Green, J.A., Guilford, et al. (2017). Breeding density, fine-scale tracking, and large-scale modelling reveal the regional distribution of four seabird species. Ecological Applications, 27(7), 2074-2091.

Wakefield, E.W., Owen, E., Baer, J., Daunt, F., Dodd, L.S., Green, J.A., Guildford, T., Mavor, R., et al. (2019). Erratum to Wakefield et al. 2017. Breeding density, fine‐scale tracking, and large‐scale modelling reveal the regional distribution of four seabird species. Ecological Applications. 27:2074–2091. Ecological Applications, 29(3), 2019, e01885.

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 No. 724.

Annex A SPA and non-SPA breeding season apportioning results based on the NatureScot method (2018)

 

Gannet

Figure A.1:
Sites Included in the Breeding Season Apportioning Calculations for Northern Gannet. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

Figure A.1: Sites Included in the Breeding Season Apportioning Calculations for Northern Gannet. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

 

Table A.1:
Apportionment of Adult Northern Gannet on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 509.4 km.

Table A.1: Apportionment of Adult Northern Gannet on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 509.4 km.

 

Guillemot

Figure A.2:
Sites Included in the Breeding Season Apportioning Calculations for Common Guillemot. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

Figure A.2: Sites Included in the Breeding Season Apportioning Calculations for Common Guillemot. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

 

Table A.2:
Apportionment of Adult Common Guillemot on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 153.7 Km. Note that these Weightings Were Used for Non-Breeding Season Apportioning as Representative of the Regional Population.

Table A.2: Apportionment of Adult Common Guillemot on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 153.7 Km. Note that these Weightings Were Used for Non-Breeding Season Apportioning as Representative of the Regional Population.

 

Herring gull

Figure A.3:
Sites Included in the Breeding Season Apportioning Calculations for Herring Gull. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

Figure A.3: Sites Included in the Breeding Season Apportioning Calculations for Herring Gull. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

 

Table A.3:
Apportionment of Adult Herring Gull on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 85.6 Km. Note that these Weightings Were Used for Non-Breeding Season Apportioning as Representative pf the Regional Population.

Table A.3: Apportionment of Adult Herring Gull on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 85.6 Km. Note that these Weightings Were Used for Non-Breeding Season Apportioning as Representative pf the Regional Population.

 

Lesser black-backed gull

Figure A.4:
Sites Included in the Breeding Season Apportioning Calculations for Lesser Black-Backed Gull. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

Figure A.4: Sites Included in the Breeding Season Apportioning Calculations for Lesser Black-Backed Gull. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

 

Table A.4:
Apportionment of Adult Lesser Black-Backed Gull on Site for Spas and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 236 Km.

Table A.4: Apportionment of Adult Lesser Black-Backed Gull on Site for Spas and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 236 Km.

 

Puffin

Figure A.5:
Sites Included in the Breeding Season Apportioning Calculations for Atlantic Puffin. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

Figure A.5: Sites Included in the Breeding Season Apportioning Calculations for Atlantic Puffin. The Orange Area Is the Site of the Proposed Development. The Red Areas Represent the SPAs and the Blue Areas Represent the Non-Designated Sites Included in the Apportioning Calculations.

 

Table A.5:
Apportionment of Adult Atlantic Puffin on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 265.4 km.

Table A.5: Apportionment of Adult Atlantic Puffin on Site for SPAs and Non-Designated Breeding Populations. Mean Max Foraging Range + 1 SD = 265.4 km.


Annex B SPA and non-SPA breeding season apportioning results from the MSS method in the MS Tool

Kittiwake

Table :
B.1: Apportionment of Adult Kittiwake on Site for SPAs and Non-Designated Breeding Populations, Using the MS Tool.

Table B.1: Apportionment of Adult Kittiwake on Site for SPAs and Non-Designated Breeding Populations, Using the MS Tool.

Guillemot

Table :
B.2: Apportionment of Adult Guillemot on Site for SPAs and Non-Designated Breeding Populations, Using the MS Tool.

Table B.2: Apportionment of Adult Guillemot on Site for SPAs and Non-Designated Breeding Populations, Using the MS Tool.

Razorbill

Table :
B.3: Apportionment of Adult Razorbill on Site for SPAs and Non-Designated Breeding Populations, Using the MS Tool.

Table B.3: Apportionment of Adult Razorbill on Site for SPAs and Non-Designated Breeding Populations, Using the MS Tool.


Annex C Assignment of subsites to spa for the application of the MS tool

 

Full Annex provided in separate document.

 

Open ▸

Annex D Apportionment of seasonal mortality estimates to SPAs and non-SPAs

 

Full Annex provided in separate document    Open ▸

 

[1] The different lists of SPAs between screening and apportioning breeding season connectivity are due to the different approaches to measuring distances between the SPA and the Development Array area.