Investigating trophic relationships of pinnipeds in Alaska and Washington using stable isotope ratios of nitrogen and carbon
Investigating trophic relationships of pinnipeds in Alaska and Washington using stable isotope ratios of nitrogen and carbon
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DOI：
10.1111/j.1748-7692.1997.tb00615.x
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发表时间：
1997-01-01
影响因子：
2.3
通讯作者：
Piatt, JF
中科院分区：
文献类型：
--
作者：
Hobson, KA;Sease, JL;Piatt, JF
我们测量了稳定氮（δ（15）N）和稳定碳7只北方海狗肌肉和毛发的δ ~（13）C同位素比值（Callorhinus ursinus）从Pribilof群岛，阿拉斯加，和27斯特勒海狮（Eumetopias jubatus）和14只斑海豹（Phoca vitulina）来自阿拉斯加湾和华盛顿海岸的惊吓，以对比来自同位素的饮食信息与现有的常规饮食研究。肌肉的稳定氮同位素分析显示，海豹比海狮更富含氮（平均δ（15）N = 18.6千分之比17.5千分之），海狮比北方海狗更富含氮（平均δ（15）N = 16.6千分之）。这些物种之间的营养隔离可能主要是由于对鲱鱼（鲱鱼），鲭鱼（Pleurogrdmmus）和大的差异依赖。小狭鳕鱼。根据它们的δ（15）N值，成年雄性斯特勒海狮显示出比成年雌性更高的营养地位（平均δ（15）N：18.0千分之比17.2千分之比），而成年雌性北方海狗的营养地位高于幼年雄性海狗（平均δ（15）N：16.5千分之比15.0千分之比）。这些观察到的差异中的每一个可能是由于对鱿鱼的不同依赖或所消费的鳕鱼的大小范围的差异。三只北方海狗幼崽表现出比成年海狗更高的δ（15）N富集（平均17.7 ppm对15.8 ppm），这是因为它们依赖母乳。对头发的稳定碳同位素测量显示，随着纬度的增加，头发的稳定碳同位素值更趋于负值。在华盛顿海岸附近的斯特勒海狮和斑海豹之间的毛三角洲（13）C中的分离（平均三角洲（13）C：-13.6 ‰ vs-15.0 ‰）反映了斑海豹与来自哥伦比亚的淡水输入的更大联系。我们的研究证明了稳定同位素方法的实用性，以增加鳍足类和其他海洋哺乳动物的传统饮食分析。
We measured stable-nitrogen (delta(15)N) and stable-carbon (delta(13)C) isotope ratios in muscle and hair from 7 northern fur seals (Callorhinus ursinus) from the Pribilof Islands, Alaska, and 27 Steller sea lions (Eumetopias jubatus), and 14 harbor seals (Phoca vitulina) from the Gulf of Alaska and coast of Washington Scare, in order to contrast dietary information derived from isotopic vs. available conventional dietary studies. Stable-nitrogen-isotope analysis of muscle revealed that harbor seals were enriched over sea lions (mean delta(15)N = 18.6 parts per thousand vs. 17.5 parts per thousand) which were in Nn enriched over northern fur seals (mean delta(15)N = 16.6 parts per thousand. Trophic segregation among these species likely results primarily from differential reliance on herring (Clupea harengus), Atka mackerel (Pleurogrdmmus monopterygius), and large us. small walleye pollock (Theregra chalcogramma). According to their delta(15)N values, adult male Steller sea lions showed a higher trophic position than adult females (mean delta(15)N: 18.0 parts per thousand vs. 17.2 parts per thousand) whereas adult female northern fur seals were trophically higher than juvenile male fur seals (mean delta(15)N: 16.5 parts per thousand vs. 15.0 parts per thousand). Each of these observed differences likely resulted from differential reliance on squid or differences in the size range of pollock consumed. Three northern fur seal pups showed higher delta(15)N enrichment over adults (mean 17.7 parts per thousand vs. 15.8 parts per thousand) due to their reliance on their mother's milk. Stable-carbon isotope measurements of hair revealed a dine toward more negative values with latitude. Segregation in hair delta(13)C between Steller sea lions and harbor seals off the coast of Washington (mean delta(13)C: -13.6 parts per thousand vs. -15.0 parts per thousand) reflected the greater association of harbor seals with freshwater input from the Columbia River. Our study demonstrates the utility of the stable isotope approach to augment conventional dietary analyses of pinnipeds and other marine mammals.