Abstract
In August 2021 Energinet commissioned the Danish Center for Environment and Energy (DCE), Aarhus University, in collaboration with Univ. of St. Andrews, Scotland, to carry out an assessment of the potential effects on bird distributions in and around the Hesselø OWF area in southeastern Kattegat.
Results from seven aerial line transect surveys of birds, conducted in relation to the above wind farm plans, was used to present data on bird abundance and distribution. This was supplemented by bird survey data from the Danish national monitoring program, NOVANA, from which data were selected from a larger area from the winters of 2008, 2013, 2016 and 2020. Based on these data, persistency maps could be modelled for each of the species/species groups, across all surveys. Persistency maps indicate where the bird utilize an area more intensively than other parts. Thus, persistency maps also indicate areas of higher sensitivity for the species.
From a list of bird species recorded within the study area, four species or species groups were selected for further analysis. The selection of the species was based on their abundance in and near the potential Hesselø OWF, combined with the conservation status of each species. Red-throated Diver/Black-throated Diver, Northern Gannet, Black-legged Kittiwake and Razorbill/Common Guillemot were the four species/species groups selected.
Through a literature study, the effect from offshore wind farms on the distribution of the above four species/species groups was assessed, on basis of which displacement scenarios could be determined. Using these scenarios, the number of displaced birds pr. species/species group could be estimated. Also, the potential change in distribution between the winter 2020 distribution and other mid-winter survey could be assessed, including the re-distribution of displaced birds. These assessments indicate how a wind farm project in the area could add to a cumulative effect on the selected species.
Red-throated Diver/Black-throated Diver was found in low numbers in the vicinity of the proposed wind farm site. Being listed on Appendix 1 of the EU Birds Directive, this species group was included in the analysis. Less than 0.1 % of the flyway population was displaced.
Gannet and Kittiwake was present in the proposed wind farm area in very fluctuating numbers. The number of displaced birds for the two species was less than 0.01 and 0.002 % of the flyway populations, respectively.
Razorbill/Common Guillemot was found to be the most abundant species group in and near the proposed wind farm area, appearing in highly fluctuating numbers. They could not be identified to species, and each of the two species consist of more subpopulations. The subpopulation composition in the study area is poorly known, but under described assumptions the estimated percentage of displaced birds was approximately 0.5 % of the Razorbill ssp. torda population, 0.2 % of the Razorbill ssp. islandica, 0.03 % for Common Guillemot ssp. aalge (East Atlantic), and 0.04 % for Common Guillemot ssp. albionis.
Results from seven aerial line transect surveys of birds, conducted in relation to the above wind farm plans, was used to present data on bird abundance and distribution. This was supplemented by bird survey data from the Danish national monitoring program, NOVANA, from which data were selected from a larger area from the winters of 2008, 2013, 2016 and 2020. Based on these data, persistency maps could be modelled for each of the species/species groups, across all surveys. Persistency maps indicate where the bird utilize an area more intensively than other parts. Thus, persistency maps also indicate areas of higher sensitivity for the species.
From a list of bird species recorded within the study area, four species or species groups were selected for further analysis. The selection of the species was based on their abundance in and near the potential Hesselø OWF, combined with the conservation status of each species. Red-throated Diver/Black-throated Diver, Northern Gannet, Black-legged Kittiwake and Razorbill/Common Guillemot were the four species/species groups selected.
Through a literature study, the effect from offshore wind farms on the distribution of the above four species/species groups was assessed, on basis of which displacement scenarios could be determined. Using these scenarios, the number of displaced birds pr. species/species group could be estimated. Also, the potential change in distribution between the winter 2020 distribution and other mid-winter survey could be assessed, including the re-distribution of displaced birds. These assessments indicate how a wind farm project in the area could add to a cumulative effect on the selected species.
Red-throated Diver/Black-throated Diver was found in low numbers in the vicinity of the proposed wind farm site. Being listed on Appendix 1 of the EU Birds Directive, this species group was included in the analysis. Less than 0.1 % of the flyway population was displaced.
Gannet and Kittiwake was present in the proposed wind farm area in very fluctuating numbers. The number of displaced birds for the two species was less than 0.01 and 0.002 % of the flyway populations, respectively.
Razorbill/Common Guillemot was found to be the most abundant species group in and near the proposed wind farm area, appearing in highly fluctuating numbers. They could not be identified to species, and each of the two species consist of more subpopulations. The subpopulation composition in the study area is poorly known, but under described assumptions the estimated percentage of displaced birds was approximately 0.5 % of the Razorbill ssp. torda population, 0.2 % of the Razorbill ssp. islandica, 0.03 % for Common Guillemot ssp. aalge (East Atlantic), and 0.04 % for Common Guillemot ssp. albionis.
| Original language | English |
|---|---|
| Place of Publication | Copenhagen |
| Publisher | Danish Energy Agency |
| Commissioning body | Energinet |
| Number of pages | 141 |
| Publication status | Published - 13 Dec 2021 |