Pacific Walrus (Odobenus rosmarus divergens) Resource Selection in the Northern Bering Sea
Pacific Walrus (Odobenus rosmarus divergens) Resource Selection in the Northern Bering Sea
复制标题
北白令海太平洋海象 (Odobenus rosmarus divergens) 资源选择
作者：
C. Jay;J. Grebmeier;A. Fischbach;T. Mcdonald;L. Cooper;F. Hornsby
太平洋海象是一种大型底栖动物，每年活动范围横跨白令海和楚科奇海的大陆架。我们使用离散选择模型来估计成年无线电标记海象的地点选择，相对于 2006 年、2008 年和 2009 年白令海北部（圣劳伦斯岛冰间湖）著名海象越冬区底栖动物群热量生物量的可用性和海冰浓度。研究区域中优势大型动物群总热量生物量的至少 60% 由双壳类纲 Nuculidae、Tellinidae 和 Nuculanidae。模型估计表明，海象的地点选择与双壳类动物热量生物量分布关系最为密切，并且海象从可用的大部分高冰浓度中选择了较低的冰浓度（四分位数：76％、93％和99％）。预测海象选址平均值较高的区域通常与其他研究中确定的有机碳输入较高的区域一致。预计圣劳伦斯岛冰间湖海冰的减少以及该地区双壳类动物可能随之减少，可能会导致白令海北部海象的越冬地向北移动。
The Pacific walrus is a large benthivore with an annual range extending across the continental shelves of the Bering and Chukchi Seas. We used a discrete choice model to estimate site selection by adult radio-tagged walruses relative to the availability of the caloric biomass of benthic infauna and sea ice concentration in a prominent walrus wintering area in the northern Bering Sea (St. Lawrence Island polynya) in 2006, 2008, and 2009. At least 60% of the total caloric biomass of dominant macroinfauna in the study area was composed of members of the bivalve families Nuculidae, Tellinidae, and Nuculanidae. Model estimates indicated walrus site selection was related most strongly to tellinid bivalve caloric biomass distribution and that walruses selected lower ice concentrations from the mostly high ice concentrations that were available to them (quartiles: 76%, 93%, and 99%). Areas with high average predicted walrus site selection generally coincided with areas of high organic carbon input identified in other studies. Projected decreases in sea ice in the St. Lawrence Island polynya and the potential for a concomitant decline of bivalves in the region could result in a northward shift in the wintering grounds of walruses in the northern Bering Sea.