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首页> 外文期刊>Russian journal of marine biology >Sea Ice-Upper Ocean Ecosystems and Global Changes in the Arctic
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Sea Ice-Upper Ocean Ecosystems and Global Changes in the Arctic

机译：海冰-上层海洋生态系统与北极的全球变化

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摘要

In the Arctic, a clear temperature trend toward warming has been observed during the last two decades. The warming has led to a reduction in the area and thickness of the Arctic sea ice cover because of increased melting. Melt water is accumulated within the 0- to 30-m surface layer, markedly changing its hydro-logical and hydrochemical characteristics: this water is warmer and fresher, with lower nutrient concentrations. A stable thermocline at depths of 30-35 m weakens vertical mixing of water and hampers active exchange between nutrient-enriched water lying below the thermocline and nutrient-poor water under ice. This affects the qualitative and quantitative composition of upper-ocean phyto- and zooplankton. The changes in the climate and the ice environment cause marked alterations in the composition and structure of the biological communities of sea ice and under-ice surface water. Comparative analysis of materials collected in the anticyclonic Arctic Gyre at the ice stations Severnyi Polyus-22 (1975- 1981) and SHEBA (1997-1998) shows that over the last two decades the number of species of ice diatoms markedly decreased and the role of freshwater algae increased. The number of nematodes, copepods, amphipods, and turbellarians, which were the dominant groups in perennial ice, also declined sharply. The results suggest that the sea ice-upper ocean ecosystem is changing from typically marine to brackish-water. The main reason for these changes is probably global warming in the Arctic.
机译：在过去的二十年中，北极地区出现了明显的升温趋势。由于融化增加，变暖导致北极海冰覆盖面积和厚度减小。融化水积聚在0至30 m的表层内，从而显着改变了其水文和水化学特性：该水更温暖，更新鲜，营养成分含量更低。深度为30-35 m的稳定的温跃层会削弱水的垂直混合，并阻碍位于温跃层以下的营养丰富的水和冰下营养不良的水之间的主动交换。这影响了上层海洋植物和浮游动物的定性和定量组成。气候和冰环境的变化导致海冰和冰底地表水生物群落的组成和结构发生明显变化。对在冰场Severnyi Polyus-22（1975-1981）和SHEBA（1997-1998）的反气旋北极旋流中收集的材料进行的比较分析表明，在过去的二十年中，硅藻的种类数量显着减少，并且硅藻的作用淡水藻类增加。线虫，co足纲动物，两栖纲动物和turbellarians的数量，在多年生冰中占主导地位，也急剧下降。结果表明，海冰上层海洋生态系统正在从典型的海洋变为微咸水。这些变化的主要原因可能是北极地区的全球变暖。

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