HUMPBACK WHALE (Megaptera novaeangliae): Gulf of Maine Stock

• Main Authors: Stock Definition, Geographic Range
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2002
• Subjects: Bear Island; Christensen; Greenland; Jan Mayen; Newfoundland; Norway; Humpback Whale; Iceland; Megaptera novaeangliae; North Atlantic; Northern Norway
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.295.166; http://www.nmfs.noaa.gov/pr/pdfs/sars/ao2002whhb-gme.pdf

In the western North Atlantic, humpback whales feed during spring, summer and fall over a range which encompasses the eastern coast of the United States (including the Gulf of Maine), the Gulf of St. Lawrence, Newfoundland/Labrador, and western Greenland (Katona and Beard 1990). Other North Atlantic feeding grounds occur off Iceland and northern Norway, including off Bear Island and Jan Mayen (Christensen et al. 1992; Palsbøll et al. 1997). These six regions represent relatively discrete subpopulations, fidelity to which is determined matrilineally (Clapham and Mayo 1987). Genetic analysis of mitochondrial DNA (mtDNA) has indicated that this fidelity has persisted over an evolutionary timescale in at least the Icelandic and Norwegian feeding grounds (Palsbøll et al. 1995; Larsen et al. 1996). Previously, the North Atlantic humpback whale population was treated as a single stock for management purposes (Waring et al. 1999). Indeed, earlier genetic analyses (Palsbøll et al. 1995), based upon relatively small sample sizes, had failed to discriminate among the four western North Atlantic feeding areas. However, genetic analyses often reflect a timescale of thousands of years, well beyond those commonly used by managers. Accordingly, the decision was recently made to reclassify the Gulf of Maine as a separate feeding stock; this was based upon the strong fidelity by individual whales to this region, and the attendant assumption that, were this subpopulation wiped out, repopulation by immigration from adjacent areas would not occur on any reasonable