STRIPED DOLPHIN (Stenella coeruleoalba): Western North Atlantic Stock

STOCK DEFINITION AND GEOGRAPHIC RANGE The striped dolphin, Stenella coeruleoalba, is distributed worldwide in temperate and tropical seas of the world. Striped dolphins are found in the western North Atlantic from Nova Scotia south to at least Jamaica and in the Gulf of Mexico. In general, striped dolphins appear to prefer continental slope waters offshore to the Gulf Stream (Leatherwood et al. 1976; Perrin et al. 1994; Schmidly 1981). There is no information concerning striped dolphin stock structure in the western North Atlantic. In waters off the northeastern U.S. coast, striped dolphins are distributed along the continental shelf edge from Cape Hatteras to the southern margin of Georges Bank, and also occur offshore over the continental slope and rise in the midAtlantic region (CETAP 1982). Continental shelf edge sightings in this program were generally centered along the 1,000 m depth contour in all seasons (CETAP 1982). During 1990 and 1991 cetacean habitat-use surveys, striped dolphins were associated with the Gulf Stream north wall and warm-core ring features (Waring et al. 1992). Striped dolphins seen in a survey of the New England Sea Mounts (Palka 1997) were in waters that were between 20 to 27C and deeper than 900 m. Sightings of striped dolphins between Cape Hatteras, NC and the Atlantic side of Florida have not been documented in dedicated sighting surveys (Palka 1997), though there are records of strandings on beaches from North Carolina to Florida (Smithsonian database). Although striped dolphins are considered to be uncommon in Canadian Atlantic waters (Baird et al. 1993), recent summer sightings (2-125 individuals) in the deeper and warmer waters of the Gully (submarine canyon off eastern Nova Scotia shelf) suggest that this region may be an important part of their range (Gowans and Whitehead 1995; Baird et al. 1997).