DISSOLVING STOCK DISCRETENESS WITH SATELLITE TRACKING: BOWHEAD WHALES IN BAFFIN BAY

• Published in: Marine mammal science Vol. 22; no. 1; pp. 34 - 45
• Main Authors: Heide-JØrgensen, M. P., Laidre, K. L., Jensen, M. V., Dueck, L., Postma, L. D.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Science Inc 01.01.2006; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Balaena mysticetus; Biological and medical sciences; bowhead whale; Canadian High Arctic; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Mammalia; satellite tracking; stock identification; Teledetection and vegetation maps; Vertebrata; West Greenland; Baffin Bay; Arctic Region; West Greenland; Range finding; stock identification; Canadian High Arctic; Remote sensing; Balaena mysticetus; Marine environment; Canada; Vertebrata; Mammalia; Satellite tracking; Cetacea; Stock; bowhead whale
• ISSN: 0824-0469; 1748-7692
• DOI: 10.1111/j.1748-7692.2006.00004.x

Nine bowhead whales (Balaena mysticetus) were instrumented with satellite transmitters in West Greenland in May 2002 and 2003. Transmitters were either encased in steel cans or imbedded in floats attached to wires. Transmitters mounted in steel cans had a high initial failure rate, yet those that were successful provided tracking durations up to seven months. Float tags had a low initial failure rate and initially provided large numbers of positions; however, they had deployment durations of only 2–33 d. All tracked whales departed from West Greenland and headed northwest towards Lancaster Sound in the end of May. Three tags with long tracking durations (197–217 d) recorded movements of whales (1 ♂, 2 ♀) into December in 2002 and 2003. All of these individuals remained within the Canadian High Arctic or along the east coast of Baffin Island in summer and early fall. By the end of October, all three whales moved rapidly south along the east coast of Baffin Island and entered Hudson Strait, an apparent wintering ground for the population. One of the whales did not visit Isabella Bay on east Baffin Island, the locality used for abundance estimation from photographic reidentification of individuals. The movements of whales tagged in this study raise critical questions about the assumed stock discreteness of bowhead whales in Foxe Basin, Hudson Strait, and Davis Strait and indicate current estimates of abundance are negatively biased.