Exploitation of mesoscale oceanographic features by grey-headed albatross Thalassarche chrysostoma in the southern Indian Ocean
Exploitation of mesoscale oceanographic features by grey-headed albatross Thalassarche chrysostoma in the southern Indian Ocean
复制标题
南印度洋灰头信天翁 Thalassarche chrysostoma 对中尺度海洋学特征的开发
DOI：
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发表时间：
2001
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影响因子：
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通讯作者：
Ntw Klages
中科院分区：
文献类型：
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作者：
DC Nel;J. Lutjeharms;E. Pakhomov;I. Ansorge;P. Ryan;Ntw Klages
1997年11月至12月和1998年1月至2月期间在马里恩岛（爱德华王子群岛）追踪到的繁殖灰头信天翁Thalassarche chrysostoma，显示出与南印度洋海面高度异常所确定的中尺度海洋学特征密切相关。在孵化期间，大多数鸟类在岛的北部觅食，在亚热带辐合带和亚南极带的阿古拉斯回流造成的异常边缘。相比之下，在养鸡期间，所有追踪的鸟类都在岛屿的西南部，沿着西南印度脊的异常边缘觅食。先前在这一领域的研究表明，这些异常实际上是南极绕极流穿过西南印度洋脊时产生的涡流。雏鸡饲养期间的饲料样本显示，新鲜的掠食性鱼Magnisudis prionosa和鱿鱼Martialia hyadesi占优势。在我们的样本中也很好地代表了绿足鼠捕食的真菌鱼和片脚类动物。从被追踪的鸟类身上采集的饮食样本显示，在阳性异常边缘进食的鸟类带着新鲜的prionosa和hyadesi样本返回。因此，掠食性鱼类和鱿鱼可能集中在这些特征上。在西南印度洋脊形成的涡流也被证明向马里恩岛附近漂移，在马里恩岛上繁殖的企鹅和海豹的觅食范围内。因此，我们认为这些中尺度海洋学特征可能是“生命支持”系统的重要组成部分，使全球重要的海鸟和海豹种群能够在爱德华王子群岛繁殖。
Breeding grey-headed albatross Thalassarche chrysostoma, tracked from Marion Island (Prince Edward Islands) during November-December 1997 and January-February 1998, showed a strong association with mesoscale oceanographic features, as identified by sea surface height anomalies, in the southern Indian Ocean. During incubation, most birds foraged to the north of the island, at the edges of anomalies created by the Agulhas Return Current in the Subtropical Convergence and the Subantarctic zones. In contrast, during chick-rearing all tracked birds foraged to the south-west of the island, at the edges of anomalies along the South-West Indian Ridge. Previous work in this area has shown that these anomalies are in fact eddies that are created as the Antarctic Circumpolar Current crosses the South-West Indian Ridge. Diet samples taken during the chick-rearing period showed a predominance of fresh specimens of the predatory fish Magnisudis prionosa and the squid Martialia hyadesi. Myctophid fish and amphipods Themisto gaudichaudii, both known prey of M. hyadesi, were also well represented in our samples. Diet samples taken from tracked birds showed birds feeding at edges of positive anomalies returning with fresh specimens of M. prionosa and M. hyadesi. Predatory fish and squid are thus presumably concentrated at these features. Eddies formed at the South-West Indian Ridge have also been shown to drift closer to Marion Island, within the foraging range of penguins and seals breeding on Marion Island. We therefore suggest that these mesoscale oceanographic features may be an important component of the 'life-support' system enabling globally significant populations of seabirds and seals to breed at the Prince Edward Islands.