Evaluation of condition indices relating to seasonal changes and diet of harp seals, Phoca groenlandica Erxleben 1777

Indices of nutritional condition and diet were evaluated in harp seals Phoca groenlandica obtained from hunters in Hudson Strait and the Gulf of St. Lawrence, December 1988 to October 1990. In winter seals, blubber and the lean, eviscerated carcass contributed 90% and 9% of total body lipids, respec...

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Bibliographic Details
Main Author: Beck, Gregor Gilpin
Format: Thesis
Language:English
Published: McGill University 1990
Subjects:
Online Access:http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59938
Description
Summary:Indices of nutritional condition and diet were evaluated in harp seals Phoca groenlandica obtained from hunters in Hudson Strait and the Gulf of St. Lawrence, December 1988 to October 1990. In winter seals, blubber and the lean, eviscerated carcass contributed 90% and 9% of total body lipids, respectively. Lipid was distributed homogeneously throughout the blubber. Blubber thickness and girth at 50% of length showed the strongest correlation to fat stores. Sculp and core mass in females increased from autumn to winter. Mature males were observed to significantly increase their blubber mass from early to late winter. Muscle and liver lipid content varied seasonally in both sexes, and were highest in a sample of females one month post-partum which were feeding very intensively. These females had reduced blubber mass and blubber lipid content, but the highest observed core mass, the later being significantly heavier than in autumn. Changes in nutritional condition reflect seasonal variation in feeding intensity.