USE OF COASTAL WATERS AROUND LUNDY ISLAND BY MARINE MAMMALS AND SEABIRDS

• Main Author: Hodgson-Ball, Katharine R
• Other Authors: Faculty of Science and Technology
• Format: Thesis
• Language: English
• Published: Plymouth University 2012
• Subjects: Cetaceans; Grey seals; Habitat use; Foraging; Theodolite tracking; MCZ; Renewable energy; Balaenoptera acutorostrata
• Online Access: http://hdl.handle.net/10026.2/1786

A large-scale windfarm development is being proposed 13 km north of Lundy Islands’ Marine Conservation Zone (MCZ), providing a potential threat to the protected ecosystems. Of particular significance is the effect this development could have on the mobile species that utilise these waters, such as marine mammals and seabirds. The use of the waters around Lundy by marine megafauna, cetaceans in particular, is largely unknown, and research into the spatial distribution and habitat use of local populations is required. This study involved six weeks and 186 hours of cliff based observations from various locations around Lundy Island. Scans were carried out every 30 minutes, recording any marine mammals and foraging seabirds and a theodolite was used to track cetacean movement in the surrounding coastal waters. As well as analysis of previous sightings data, the data collected was analysed for the influence of topographical and environmental features on distribution and habitat use. This study found that the coastal waters around Lundy were used by common dolphins (Delphinus delphis), harbour porpoises (Phocoena phooena) and in fewer numbers minke whales (Balaenoptera acutorostrata), bottlenose dolphins (Tursiops truncatus) and risso’s dolphins (Grampus griseus), with peak sightings in summer months. Foraging behaviour was observed, primarily on the east coast of the Island over sandbank habitat, potentially feeding on the sandeel population supported by the sandbanks on this coastline. It was unclear whether grey seals are foraging in the waters surrounding the Island; however, it is possible that they are exploiting the local sandeel population. The windfarm development may provide a barrier to cetaceans and grey seals foraging in areas north of Lundy Island. Proximity of Lundy to the development may result in avoidance behaviour of cetacean species during the construction phase, harbour porpoises in particular, due to sound emissions during pile-driving. However, due to the long time-scale of the development, animals may become habituated to the pile driving emissions and would be likely to re-inhabit the area once the construction phase is complete.