Abstract
This appendix supplements the Kincardine Offshore Wind Farm Environmental Statement.
The Kincardine Offshore Wind Farm (“Kincardine”) project aims to develop a pilot-scale offshore wind farm utilising floating foundation technology, which will demonstrate the technological and commercial feasibility of floating offshore wind.
The project site is located inside the Scottish Territorial Waters (“STW”) to the east of Stonehaven and south-east of Aberdeen, and is approximately 15 kilometres (“km”) from the Kincardineshire coast at its closest point.
HiDef Aerial Surveying Limited (“HiDef”) was contracted to undertake a monthly series of high resolution digital video aerial surveys of marine mammals and birds around the Kincardine project and an 8km buffer between April 2013 and September 2014.
The site is not located within a marine protected area, but is located close to a number of important seabird colonies, some of which are designated under the European Council (“EC”) Directive 2009/147/EC on the conservation of wild birds (“the Birds Directive”) as Special Protection Areas (“SPA”).
HiDef’s bespoke GEN II high-resolution digital video system was mounted into an aircraft to sample a 500m-wide strip of the sea, with each survey comprising seven transects across the study area. A standard process for reviewing video footage was used to detect objects with a high level of quality control to ensure all objects present were detected.
The detected objects were assessed by expert ornithologists and marine mammal scientists to identify them to species level, following the same quality control process. Robust statistical analysis of the data was used to estimate the abundance and distribution of birds and mammals during the surveys.
In addition, assessments were made of the effect of availability bias on the abundance of guillemot Uria aalge, razorbill Alca torda, puffin Fratercula arctica and harbour porpoise Phocoena phocoena using known diving rates for the species. Data are provided on the flying direction, behaviour and calculated flying height of birds using HiDef’s patented parallax technique.
Sixteen surveys were completed as planned between 1 May 2013 and 29 September 2014. A total of 32,960 birds of 20 species and 138 non-avian animals of seven species were recorded during the project. The overall identification rate to species level was 93.7%.
Fulmar Fulmarus glacialis were recorded at low density in the study area, but showed evidence of connection with local colonies as well as possibly with colonies to the south and north of the study area. Fulmars were recorded flying at low heights above the sea which would put them at low risk of collision with wind turbines.
Gannet Morus bassanus was recorded at mostly low density in the study area. Their flying direction was largely parallel to the coast, implying connection with the nearest major colony for the species at Bass Rock in the Firth of Forth. Approximately 14% of gannet were recorded flying over 20m above sea level (“ASL”) and therefore have the potential to be at risk of collision with wind turbine blades.
Kittiwake Rissa tridactyla was the second most commonly recorded species in the study area and was present at moderately high density during the spring, summer and early autumn. While approximately 36% of kittiwakes may have been flying to and from local colonies to feed in the study area, there was evidence that a greater proportion were likely to have been using other colonies to the north and south of the study area. Most kittiwakes were recorded flying at sea level, but 13.6% were recorded flying more than 20m above the sea and thus have the potential for impact with wind turbine blades.
Herring gull Larus argentatus was recorded at very low density in the study area, lower than in historical boat-based surveys of the region in the 1980s and 1990s. This is likely to be evidence of a decline in numbers of this species at sea in the area. Although a number of herring gulls were recorded flying at turbine blade height, their numbers were too low to calculate a reliable estimate of flying heights for the species.
Guillemot was the most abundant species recorded during the surveys with densities considerably higher than in historical boat-based surveys of the area. With an estimated number of over 56,000 present in the study area in July 2013, these were unlikely to have arrived in this area solely from colonies on the adjacent coastline. In the breeding season and post-breeding period it is likely that birds from colonies further afield were using the site on an opportunistic basis. In spite of the large numbers, guillemots are not classified as a high collision risk species, on account of the fact that they fly less than other species and due to the very low percentage recorded flying above 20m.
Razorbill was present in the study area at moderately high density and while the numbers present were consistent with the numbers breeding at local colonies, there was evidence from the flight directions that a small proportion of birds using the study area originated from colonies to the north or south. Like guillemot, this species spent very little of its time flying and nearly all birds were found to be flying below 20m.
Moderate densities of puffin were recorded and in numbers high enough to suggest that a proportion of the birds present were likely to be non-breeding birds from colonies further away than the coastal stretch between Dundee and Peterhead. Flying heights were low and nearly all below a minimum turbine blade height of 20m.
Harbour porpoise were present at low density in the survey area and the Kincardine project site. At their peak in July and, when corrected for availability bias, estimates were higher than predictions of absolute density during SCANS surveys in July 2004. Population estimates for the Project Site were less than 0.02% of the European population for this species, and less than 0.2% of the regional population.
There was a high degree of consistency in the density estimates for most species between the two summers of survey. The only exception was for puffin, in which densities were about an order of magnitude lower in the summer period of 2014, and suggests that the concentrations recorded in the summer of 2013 were somewhat ephemeral in nature.
Corrections were made to the relative abundance of guillemots, razorbills, puffins and harbour porpoise to give approximations of absolute abundance using known dive rates for these species, but these were likely to be inaccurate for the first three species out with the breeding season for seabirds. This study exposed potential problems with using correction factors based upon known diving rates for harbour porpoise.
Large fluctuations in the density of all seabird species between months makes prediction of the potential impact of a wind farm difficult. It is suggested here that these fluctuations may be related to differing effects of an oceanographic front that extends north to south off the coast of Aberdeenshire.