BLUE WHALE (Balaenoptera musculus): Western North Atlantic Stock

• Main Authors: Stock Definition, Geographic Range
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1995
• Subjects: CURRENT AND MAXIMUM NET PRODUCTIVITY RATES; Arctic; Belle Isle; Canada; Lawrence River; Mansfield; Strait of Belle Isle; Balaenoptera musculus; Blue whale; Davis Strait; Newfoundland; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.432.9538; http://www.nefsc.noaa.gov/publications/tm/tm114/pdfs/32.pdf

The distribution of the blue whale, Balaenoptera musculus, in the western North Atlantic generally extends from the Arctic to at least mid-latitudes. Blue whales are most frequently sighted in the waters off eastern Canada, with the majority of recent records from the Gulf of St. Lawrence (Sears et al. 1987). The species was hunted around Newfoundland in the first half of the 20th century (Sergeant 1966). The present Canadian distribution, broadly described, is spring, summer, and fall in the Gulf of St. Lawrence, especially along the north shore from the St. Lawrence River estuary to the Strait of Belle Isle and off eastern Nova Scotia. The species occurs in winter off southern Newfoundland and also in summer in Davis Strait (Mansfield 1985). The blue whale is best considered as an occasional visitor in U.S. Atlantic Exclusive Economic Zone (EEZ) waters, which may be the current southern limit of its range (CeTAP 1982; Wenzel et al. 1988). All of the five sightings described in the foregoing two references were in August. Yochem and Leatherwood (1985) summarized records that suggested an occurrence of this species south to Florida and the Gulf of Mexico, although the actual southern limit of the species ’ range is unknown. The blue whale may be nomadic and open-ocean in habitat. In one example, an individual was tracked from near Newfoundland to south of Bermuda (Gagnon and Clark 1993). POPULATION SIZE Little is known about the population size of blue whales except for in the Gulf of St. Lawrence area. Here, 308 individuals have been catalogued (Sears et al. 1987). Mitchell (1974) estimated that the blue whale population in the western North Atlantic may number only in the low hundreds. R. Sears (pers. comm.) suggests that no present evidence exists to refute this estimate. Minimum Population Estimate The 308 recognizable individuals from the Gulf of St. Lawrence area which were catalogued by Sears et al. (1987) is considered to be a minimum population estimate. Current Population Trend There are insufficient ...