Distribution of steller sea lions Eumetopias jubatus in relation to spring-spawning fish in SE Alaska
Distribution of steller sea lions Eumetopias jubatus in relation to spring-spawning fish in SE Alaska
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阿拉斯加东南部北海狮 Eumetopias jubatus 的分布与春季产卵鱼的关系
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
G. Vanblaricom
中科院分区：
文献类型：
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作者：
J. Womble;M. Willson;M. Sigler;B. Kelly;G. Vanblaricom
精力充沛的需求是很高的斯特勒海狮Eumetopias jubatus在春季，当女性怀孕和哺乳期和男性正在准备延长斋戒的繁殖领土。因此，我们预测，在阿拉斯加东南部的海狮在春季的分布将受到春季产卵聚集的高能量的猎物物种（太平洋鲱鱼和Eulachon Thaleichthys pacificus）的分布。春季海狮的空间分布反映了阿拉斯加东南部北方，特别是林恩运河和沿着雅库特前陆的产卵eulachon的分布。在春季海狮数量的高峰Haulouts位于显着接近eulachon产卵地点比haulouts，在一年中的其他时间达到高峰。一些haulouts被占领，只有在eulachon产卵期。海狮在春季haulouts的最大数量呈负相关的距离最近的eulachon聚集，并呈正相关的eulachon在20公里内的数量。在2002年和2003年3月至5月期间，每7至10天进行一次空中调查，发现2002年和2003年鲱鱼产卵场的水中有大量海狮;然而，鲱鱼产卵场的数量与海狮数量之间没有显着关系（距离>60公里除外）。2003年，海狮的数量在鲱鱼产卵地更大，对应于更高的鲱鱼生物量。季节性聚集，高能量的猎物物种影响海狮的季节性分布，可能是他们的繁殖成功的关键。
Energetic demands are high for Steller sea lions Eumetopias jubatus during spring, when females are pregnant and lactating and males are preparing for extended fasts on breeding territories. Therefore, we predicted that the distribution of sea lions in SE Alaska in spring would be influenced by the distribution of spring spawning aggregations of high-energy prey species (Pacific herring Clupea pallasii and eulachon Thaleichthys pacificus). The spatial distribution of sea lions during spring reflected the distribution of spawning eulachon in northern Southeast Alaska, particularly in Lynn Canal and along the Yakutat forelands. Haulouts with peak numbers of sea lions in spring were located significantly closer to eulachon spawning sites than haulouts that peaked at other times of year. Some haulouts were occupied only during the eulachon spawning period. The maximum number of sea lions at haulouts in spring was inversely correlated with the distance to the closest eulachon aggregation and was positively associated with the number of eulachon within 20 km. Aerial surveys conducted every 7 to 10 d during March through May in 2002 and 2003 revealed large numbers of sea lions in the water at herring spawning sites in 2002 and 2003; however, there were no significant relationships between the number of herring spawning sites and number of sea lions (except at distances >60 km). The number of sea lions was greater at herring spawning sites in 2003, corresponding to higher herring biomass. Seasonally aggregated, high-energy prey species influence the seasonal distribution of sea lions and may be critical to their reproductive success.