New Zealand Journal of Marine and Freshwater Research abstracts
Near-shore distribution and abundance of dolphins
along the West Coast of the South Island, New Zealand
STEFAN BRäGER
KARSTEN SCHNEIDER
Department of Marine Science
University of Otago
P. O. Box 56
Dunedin, New Zealand
Abstract Compared to other stretches of the New Zealand
coast, very little is known about the cetacean fauna off the West Coast of the
South Island. The purpose of this paper is to describe the near-shore
distribution and abundance of dolphins in that area by summarising the results
of two major studies. Between February 1995 and February 1997, 97 day trips
were undertaken from Westport, Greymouth, and Jackson Bay in a small boat to
survey the near-shore distribution of dolphins. Between July 1994 and February
1997, 283 field days were spent on the water in Doubtful Sound studying the
local bottlenose dolphin (Tursiops truncatus) population of c. 63
individuals. At the same time, three longer surveys were undertaken into other
fiords of Fiordland which indicated the presence of further populations.
Altogether, five delphinid species were recorded in various abundances.
Small-medium-sized groups of Hector's dolphins (Cephalorhynchus hectori)
with 1-60 individuals were observed in almost all areas of Westland in winter
as well as in summer. Maximum densities peaked at 5-18 individuals per nautical
mile of coastline between Cape Foulwind and Hokitika. Dusky and common dolphins
(Lagenorhynchus obscurus and Delphinus delphis) occurred almost
exclusively in summer in groups of 2-150 individuals, often with calves,
especially at Cape Foulwind and Jackson Head. Bottlenose dolphins (Tursiops
truncatus) and killer whales (Orcinus orca) were observed rarely off
Westland, but occurred more frequently in Fiordland.
Keywords abundance; Cephalorhynchus hectori;
Delphinus delphis; distribution; dolphin; environmental factors;
Lagenorhynchus obscurus; movements; New Zealand; Orcinus orca;
South Island; Tursiops truncatus; West Coast
New Zealand Journal of Marine and Freshwater Research, 1998, Vol. 32:
105-112
0028-8330/98/3201-0105 $7.00/0 (c) The Royal Society of New Zealand
1998
PDF file of entire paper: medium quality (589K); (scanned from paper original: notes about this process)
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