Cetaceans of the Atlantic Frontier, north and west of Scotland

Surveys carried out to the north and west of Scotland have recorded 15 species of cetacean between 1979 and 1998. These were fin whale (Balaenoptera physalus), sei whale (B. borealis), minke whale (B. acutorostrata), humpback whale (Megaptera novaeangliae), sperm whale (Physeter macrocephalus), northern bottlenose whale (Hyperoodon ampullatus), Sowerby's beaked whale (Mesoplodon bidens), killer whale (Orcinus orca), long-finned pilot whale (Globicephala melas), Atlantic white-sided dolphin (Lagenorhynchus acutus), white-beaked dolphin (L. albirostris), Risso's dolphin (Grampus griseus), bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus delphis) and harbour porpoise (Phocoena phocoena). Atlantic white-sided dolphin was the most abundant species in the region with a total of 6317 animals recorded. Harbour porpoise was the most frequently sighted cetacean species. The geographical distribution of sightings indicate that cetacean species have varying ecological requirements, with species such as sperm whale, pilot whale and white-sided dolphin favouring deep water off the continental shelf edge, while minke whale, white-beaked dolphin and harbour porpoise were apparently limited to the continental shelf. The diversity of species recorded in the region suggests that the Atlantic Frontier is an important habitat for cetaceans.