Stable isotope food-web analysis and mercury biomagnification in polar bears (Ursus maritimus)

Polar research

Travis W. Horton¹  Zhouqing Xie²  Joel D. Blum²  C. Page Chamberlain³  Michael Hren⁴ 

[1] Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New ZealandCorrespondence;Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109-1005, USA;Geological and Environmental Science Department, Stanford University, Stanford, CA 94305-2115, USA;Geology and Geophysics Department, Yale University, P.O. Box 208109, New Haven, CT 06520-8109, USA

关键词: Arctic;    food webs;    pelagic;    polar bears;    stable isotopes;    sympagic;   

DOI  :  10.1111/j.1751-8369.2009.00114.x

学科分类：自然科学（综合）

来源: Co-Action Publishing

【 摘 要 】

Mercury (Hg) biomagnification occurs in many ecosystems, resulting in a greater potential for toxicological effects in higher-level trophic feeders. However, Hg transport pathways through different food-web channels are not well known, particularly in high-latitude systems affected by the atmospheric Hg deposition associated with snow and ice. Here, we report on stable carbon and nitrogen isotope ratios, and Hg concentrations, determined for 26, late 19th and early 20th century, polar bear (Ursus maritimus) hair specimens, collected from catalogued museum collections. These data elucidate relationships between the high-latitude marine food-web structure and Hg concentrations in polar bears. The carbon isotope compositions of polar bear hairs suggest that polar bears derive nutrition from coupled food-web channels, based in pelagic and sympagic primary producers, whereas the nitrogen isotope compositions indicate that polar bears occupy > fourth-level trophic positions. Our results show a positive correlat...

【 授权许可】

CC BY-NC