Abundance and biomass of sub-ice mesozooplankton in the Pechora and Kara Seas in January-April 2000

Zooplankton communities under continuous ice cover in the Kara Sea and near the ice edge in the Pechora Sea were studied. Sampling was carried out from onboard nuclear ice breakers in the period January-April 2000. Breeding of a small-size opportunist species Pseudocalanus acuspes under continuous fast ice of the Gulf of Yenisei began as early as in April, though total mesozooplankton biomass (0.8 mg/m**3) was characteristic of winter condition of community. A classical spring pattern of polychaete and barnacle larvae hatching and euphausiid spawning was observed. Such conditions of the zooplankton community near the ice edge had been described earlier, but this was the first observation of a planktonic community under continuous ice of the Kara Sea.

本研究针对喀拉海（Kara Sea）连续冰盖下以及伯朝拉海（Pechora Sea）冰缘附近的浮游动物群落（zooplankton communities）展开了调查。采样工作于2000年1-4月间在核动力破冰船（nuclear ice breakers）上完成。叶尼塞湾（Gulf of Yenisei）连续固定冰（fast ice）下的小型机会主义物种（small-size opportunist species）尖刺拟哲水蚤（Pseudocalanus acuspes）的繁殖活动早在4月便已启动，尽管其中型浮游动物总生物量为0.8 mg/m³，仍符合该群落的冬季特征。本次调查观测到了多毛类（polychaete）与蔓足类幼虫（barnacle larvae）孵化、磷虾类（euphausiid）产卵的典型春季节律。此前已有针对冰缘附近浮游动物群落的相关报道，但本次研究是首次在喀拉海连续冰盖下观测到浮游群落（planktonic community）。