STOCK DEFINITION AND GEOGRAPHIC RANGE

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1999
• Subjects: Breton Island; Northwest Atlantic; Sowerby's beaked whale
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.295.362; http://www.nmfs.noaa.gov/pr/pdfs/sars/ao1999whmb-wn.pdf

Within the genus Mesoplodon, there are four species of beaked whales that reside in the northwest Atlantic. These include True's beaked whale, Mesoplodon mirus; Gervais' beaked whale, M. europaeus; Blainville's beaked whale, M. densirostris; and Sowerby's beaked whale, M. bidens. These species are difficult to identify to the species level at sea; therefore, much of the available characterization for beaked whales is to genus level only. Stock structure for each species is unknown. The distribution of Mesoplodon spp. in the northwest Atlantic is known principally from stranding records (Mead 1989; Nawojchik 1994). Off the northeast USA coast, beaked whale (Mesoplodon spp.) sightings have occurred principally along the southern edge of Georges Bank (CETAP, 1982; Waring et al. 1992; NMFS unpubl. data). Most sightings were in late spring and summer. In addition, beaked whales were also sighted in Gulf Stream features during NEFSC 1990-1995 surveys (Waring et al. 1992; Anon 1994; Tove 1995; NMFS unpubl. data). True's beaked whale is a temperate-water species that has been reported from Cape Breton Island, Nova Scotia, to the Bahamas (Leatherwood et al. 1976, Mead 1989). It is considered rare in Canadian waters (Houston 1990). Gervais's beaked whales are believed to be principally oceanic, and strandings have been reported from the mid-Atlantic Bight to Florida, into the Caribbean and the Gulf of Figure 1. Distribution of beaked whale sightings from NEFSC shipboard and aerial surveys during the summer in 1990-1995. Isobaths are at 100 m and 1,000 m. Mexico (Leatherwood et al. 1976; Mead 1989). This is the commonest species of Mesoplodon stranded along the USA Atlantic coast. The northernmost stranding was off New York (Mead 1989). Blainville's beaked whales have been reported from southwestern Nova Scotia to Florida, and are believed to be widely but sparsely distributed in tropical to warm-temperate waters (Leatherwood et al. 1976; Mead 1989). There are two records of standings in Nova Scotia which probably ...