The under-ice mesozooplankton of the Pechora and Kara Seas in the Winter-Spring period, 2000

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