Assessment of methods used to investigate the impact of offshore wind farms on seabirds

This thesis assessed the use of radar as a remote technique for monitoring seabirds in offshore locations. The study site was in the Moray Firth, Scotland, at the Beatrice oil field, where two 5 MW wind turbines were installed in the summers of 2006 and 2007. An S-band marine surveillance radar, equipped with commercially available automatic detection and tracking software was installed on the Beatrice Alpha platform to collect ornithological data. Significant amounts of radar clutter were also recorded in this offshore environment, so bespoke filters were developed, to remove non-avian tracks from the dataset. Filtered data showed temporal patterns in avian activity at the site, which could be linked to existing knowledge of the use of the site by seabirds. Flight directions during the breeding season indicated that birds using the site were also attending colonies at the East Caithness cliffs SPA to the north west. The flight speed parameter included in models of collision between birds and wind turbines was evaluated empirically using radar data. Ground speed, which is influenced by wind was highly variable, and was on average 0.707 ms-1 slower than airspeed, increasing the collisions risk relative to the model’s predictions for many birds. Boat-based visual surveys were used to investigate the impact of turbine installation on the abundance and distribution of birds at the site during the breeding season. No effect of turbine installation was detected, but environmental variation was shown to have a significant impact on bird abundance. This demonstrates the difficulty of designing impact studies that can detect the faint signal of an impact, against background variability inherent in marine environments.EThOS - Electronic Theses Online ServiceGBUnited Kingdo