RISSO'S DOLPHIN (Grampus griseus): Western North Atlantic Stock

Risso's dolphin is distributed worldwide in tropical and temperate seas. Risso's dolphins generally have an oceanic range, and occur along the Atlantic coast of North America from Florida to eastern Newfoundland (Leatherwood et al. 1976; Baird and Stacey 1990). Off the northeast USA coast,...

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Bibliographic Details
Main Authors: Stock Definition, Geographic Range
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 1999
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.294.7396
http://www.nmfs.noaa.gov/pr/pdfs/sars/ao1999dori-wn.pdf
Description
Summary:Risso's dolphin is distributed worldwide in tropical and temperate seas. Risso's dolphins generally have an oceanic range, and occur along the Atlantic coast of North America from Florida to eastern Newfoundland (Leatherwood et al. 1976; Baird and Stacey 1990). Off the northeast USA coast, Risso's dolphin is distributed along the continental shelf edge from Cape Hatteras northward to Georges Bank during the spring, summer, and autumn (CETAP 1982; Payne et al. 1984). In winter, the range begins at the mid-Atlantic bight and extends further into oceanic waters (Payne et al. 1984). In general, the population occupies the mid-Atlantic continental shelf edge year round, and is rarely seen in the Gulf of Maine (Payne et al. 1984). During 1990, 1991 and 1993, spring/summer surveys conducted in continental shelf edge and deeper oceanic waters had sightings of Risso's dolphins associated with strong bathymetric features, Gulf Stream warm-core rings, and the Gulf Stream north wall (Waring et al. 1992; Waring 1993). There is no information on stock differentiation of Risso's dolphin in the western North Atlantic. POPULATION SIZE The total number of Risso's dolphins off the eastern USA and Canadian Atlantic coast is unknown, although four estimates are available from selected regions during spring