Cetacean surveys in the Cape Verde Islands and the use of cookiecutter shark bite lesions as a population marker for fin whales

Abstract: We examined the distribution of cetaceans in the waters of the Cape Verde Islands in 2000 and 2001. Sperm whales (Physeter macrocephalus), a Yankee whaling target species in these waters, were commonly detected acoustically and visually along with smaller cetacean species, predominantly in the northeast, windward quarter of the archipelago. A group of 34 sub-adult long-fin pilot whale (Globicephala melas) skulls were found on a beach of the island of Boavista, suggesting an unusual mass stranding. Cookiecutter shark (Isistius sp.) bite lesions were detected in a possibly resident group of fin whales (Balaenoptera physalus), as well as in a humpback whale (Megaptera novaeangliae). No such lesions have been recently reported for other North Atlantic fin and humpback whales, although they were commonly described in fin and blue whales from the South Atlantic. The presence of bite lesions on these animals could represent a marker to differentiate groups of fin whales and their movement in the region. The relationship between fin whales detected in Cape Verde waters and those from other regions warrants further scrutiny using genetic and photo-identification techniques, in the context of the presence or absence of cookiecutter shark markers.

Key Words: CAPE VERDE ISLANDS; SPERM WHALE; PHYSETER; ODONTOCETES; FIN WHALE; ISISTIUS; COOKIECUTTER SHARK; BALAENOPTERA

Document Type: Research article

Pages: 383-389

Purchase Article