Distribution and biological properties of the Antarctic krill Euphausia superba DANA during winter Weddell Gyre Study (WWGS) 1989

摘要

Samplings with Bongo net and observations on the krill predators (e. g. crabeater seals, Adelie penguins) were conducted for studying distribution and biological properties of the Antarctic krill, Euphausia superba in the western Weddell Gyre during the international Winter Weddell Gyre Study in September-October 1989 on board the ice-breaker "Akademik Fedorov". Furciliae and postlarvae were abundant in the vicinity of the frontal zone which divides the waters of the Antarctic Circumpolar Current (ACC) and the Weddell Gyre. The adult krill was obtained only in the marginal ice zone. The presence of crabeater seals indicated the occurrence of the krill also in the areas to the west of Maud Rise where inflow of the Circumpolar Deep Water was recognized. These results confirm the hypothesis that the krill is distributed over the vast periphery of the Weddell Gyre but not in the interior of the western cell of the gyre. The youngest generation consisted of furciliae IV-VI and postlarvae in September. The older krill consisted of the specimens just started to mature. They were feeding (probably on ice algae) and moulting actively.