Дополнительная информация

• Авторы: Melnikov I.А.(P. P. Shirshov Institute of Oceanology, Moscow, Russia), Kolosova E.G.(M.V. Lomonosov Moscow State University, Moscow, Russia)
• Издание: Proceedings of the Arctic Regional Centre, v.3
• Год издания: 2001
• Страницы: 165-176
• Аннотация на английском языке: During the SHEBA (Surface Heat Budget in the Arctic Ocean) year-long experiment in the Canada Basin of the Arctic Ocean, stratified zooplankton tows were made between 0 m and 1000 m in the water column from December 1997 through October 1998. The species composition, distribution and biomass were determined and compared with earlier observations at the ice station “North Pole-22” (NP-22) which drifted in the same region in the mid 1970s. Mean seasonal values of silicate, phosphate, dissolved oxygen and chlorophyll a concentrations in surface and subsurface waters were also compared between SHEBA and NP-22. Against a background of remarkable environmental changes that have occurred during the last two decades we found: (1) changes in the species composition and biomass of zooplankton in the top 1000 m of the water column; (2) an appearance of species imported from the North Pacific; (3) variations in seasonal cycling of the dominant zooplankton species. Ice melting and the spring bloom commenced within the first 10 days of June at SHEBA but not until the middle of July at NP-22. Correspondingly, there was an earlier migration of copepods Calanus hyperboreus, C. glacialis, Metridia longa, Oithona similis and Pareuchaeta glacialis, the main zooplankton biomass contributors. Several North Pacific zooplankton species were found for the first time during the SHEBA drift: copepods Calanus mar-shallae, Eucalanus bungii, Metridia pacifica, Lucicutia ovaliformis, Heterorhabdus pacificus, amphipod Scina pusilla, hydromedusas Atolla tenera and Pantachogon haeckeli. These species were not found in the Canada Basin during NP-22 (1975-1976) and other expeditions that sampled this region during the 1960s and ‘70s. Recent changes in the Arctic Ocean include (1) changes in water circulation and distribution, (2) changes in the temperature of the Atlantic layer, (3) change in the Pacific inflow, (4) a noticeable shrinking of sea-ice cover especially in the marginal seas, (5) a freshening of the surface waters associated with increased runoff and sea-ice melt all forced probably by change in global atmosphere circulation We conclude that zooplankton in the Canada Basin have, similarly, undergone change and therefore provide a sensitive indicator of the response of the biological system to these physical changes.