Indication of two Pacific walrus stocks from whole tooth elemental analysis
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Full Publication: https://doi.org/10.1007/s00300-008-0432-1Product Type: Journal Article
Year: 2008
Authors: Jay, C. V., P. M. Outridge, and J. L. Garlich-Miller
Suggested Citation:
Jay, C. V., P. M. Outridge, and J. L. Garlich-Miller. 2008. Indication of two Pacific walrus stocks from whole tooth elemental analysis. Polar Biology 31:933-943. doi:10.1007/s00300-008-0432-1
Abstract
The Pacific walrus (Odobenus rosmarus divergens) is considered to be a single panmictic population for management purposes. However, studies on population structuring in this species are limited; in part, because portions of the population's range are often inaccessible. Therefore, alternative and complementary methods for investigating stock structure in the Pacific walrus are of particular interest. We used measures of elemental concentrations in whole tooth sections from ICP-MS in a discriminant analysis to investigate evidence of stock separation between walruses from two of three known breeding areas (S.E. Bering, St Lawrence, and Anadyr Gulf). Elemental compositions of teeth from female and male walruses from the S.E. Bering and St Lawrence breeding areas were significantly different, providing evidence of separate stocks. We also obtained insights into the potential relation of walruses from non-breeding areas to walruses from these breeding groups based on similarities in their dental elemental profiles.
Keywords: Walrus, stocks, subpopulations, tooth, trace elements
Annotation
The Pacific walrus (Odobenus rosmarus divergens) is considered to be a single panmictic population for management purposes. However, elemental compositions of teeth from male and female walruses from the S.E. Bering and St. Lawrence breeding areas were significantly different, providing evidence of separate stocks. Human activities such as on-shore development near haulouts or increases in marine shipping through walrus foraging areas may negatively impact walruses by causing stampedes or disturbing foraging behaviors. Any human activity that could cause differential rates of mortality in a localized walrus stock should be carefully considered.