A Scenario of the Late-Pleistocene-Holocene Changes in the Distributional Range of Antarctic Krill (Euphausia superba) |
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| Authors: | Vassly A Spiridonov |
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| Institution: | Zoologicàl Museum of the Moscow Lomonosov State University, Herzen Str. 6, Moscow 103009. |
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| Abstract: | Abstract. Oceanographic evidence along with the data on Euphausia superba distribution indicate that the reproductive range of this species is related to the southernmost core of the Antarctic Circumpolar Current (ACC), the Weddell Gyre, the Ross Gyre, and the systems of mesoscale eddies in the Bellingshausen Sea, in the Prydz Bay area. and the D'Urville Sea. During the Last Glaciation Maximum, at ca. 18 ka BP, both the Weddell and the Ross Gyres as well as near-coastal circulations probably lost their importance in the maintenance of Antarctic krill populations due to cooling of the water column and development of multi-year sea ice. Within the ACC at that time, some smaller-scale circulations related to islands and seamounts could have played a major role in controlling krill distribution. If, nevertheless. refugia for self-maintained krill populations remained in the near-coastal zone, particularly in the eastern Indian sector, geographical isolation might have caused divergence between the two species of the gregarine Cephaloidophora commonly infesting krill at present. |
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| Keywords: | Antarctic krill distribution reproductive range Pleistocene Holocene Last Glaciation Maximum |
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