Abstract
In the light of proposed offshore energy developments in the Pentland Firth and Orkney Waters, a review was conducted of sightings information for cetaceans and basking sharks. Gaps in current knowledge were identified, and recommendations made on how to interpret or use the data available in the context of providing appropriate advice to regulators on potential interactions between these marine animals and renewable devices.
Main Findings
- Nineteen cetacean species have been recorded in the Pentland Firth and Orkney Waters since 1980, 17 of these as live sightings, making it one of the richest areas in the UK.
- Six cetacean species occur regularly: harbour porpoise, minke whale, white-beaked dolphin, Risso’s dolphin, killer whale, and bottlenose dolphin.
- The basking shark and four cetacean species are casual visitors: short-beaked common dolphin, Atlantic white-sided dolphin, long-finned pilot whale and sperm whale; these four species normally inhabit offshore waters.
- Harbour porpoise (common) and long-finned pilot whales (uncommon) are recorded year round. The other regular species tend to be seasonal, mainly in summer, although increased effort & better viewing conditions at this time of year may bias patterns.
- Although areas can be identified where sightings have been concentrated, the uneven distribution of effort limits clear interpretation of distribution patterns.
- Notwithstanding potential effort biases, some areas (e.g. Scapa Flow and adjacent areas in S. Orkney, Gills Bay, Dunnet Bay and Strathy Bay on the Scottish mainland) are clearly important for cetaceans.
- Some of the proposed development sites (e.g. those in the Pentland Firth) directly overlap with important areas for cetaceans, whilst a few (e.g. Armadale) are in localities that have had little observation effort.