中文摘要：

陆架区沉积物间隙水的营养盐再生是水体营养盐补充的重要途径之一。楚科奇海陆架区中部沉积物间隙水中的营养盐分布,是物理和生物扰动较弱状态下的沉积物-水界面的典型分布。本文对中国第4次北极科学考察采集的4个多管短柱沉积物样品及多管样站位的上层水样进行分析,得到沉积物间隙水、上覆水以及水柱中营养盐数据。结果表明,沉积物间隙水各营养盐浓度均先随沉积深度增加而呈指数快速升高,记为Ⅰ层;然后进入沉积物再矿化作用与营养盐移出速率相互抵消的稳定变化层,营养盐浓度在该阶段基本不变,记为Ⅱ层;最后是营养盐缓慢递减层,记为Ⅲ层,由于该层有机质降解作用耗尽氧气,NO-3和PO3-4被还原细菌利用而失去氧离子。通过双层模式和Fick第一扩散定律,计算得出楚科奇海沉积物-水界面硅酸盐、磷酸盐和硝酸盐的扩散通量分别为1.660mmol/（m2·d）（以Si计量）、0.008mmol/（m2·d）（以P计量）、0.117mmol/（m2·d）（以N计量）（以R06站为例）。四个调查站位沉积物中硅酸盐的扩散通量分别为3.101mmol/（m2·d）（以Si计量,CC1站）、1.660mmol/（m2·d）（以Si计量,R06站）、1.307mmol/（m2·d）（以Si计量,C07站）、0.243mmol/（m2·d）（以Si计量,S23站）,含量呈现明显的纬度分布特征。沉积物间隙水N＊的分布表明,楚科奇海沉积环境具有很强的反硝化过程,沉积物脱氮作用是硝酸盐一个重要的汇。

英文摘要：

Nutrients regeneration in pore water is one of the important ways to supply nutrients of upper water column in the shelf. The pore water in sediment of the central Chukchi Sea continental shelf, showed a typical benthic distribution of nutrients at water-sediment interface,in where physical and bioturbation was weak. The nutrient samples in multi-tubular short column sediment and water column were obtained from the Forth Chinese National Arctic Research Expedition, to measure the nutrient concentrations of pore water, overlying water and water column. The results show that, the typical distribution can be separated into three layers. The first layer is the expo- nential increasing layer （Ⅰ）,in which the concentrations of nutrients increased rapidly with depth. Then was the steady layer （Ⅱ） ,the sediment demineralization was equal to the nutrient transference and nutrients＇ concentrations were substantially constant at this stage. The third layer was a slowly descending layer （Ⅲ）, in which NO3 and PO34 were reduced by bacteria and lost oxygen ions due to organic materials degradation depleting oxygen. By a two-layer mode and the Fick＇s first law of diffusion,diffusive fluxes of silicate,phosphate and nitrate in R06 station of the Chukchi Sea shelf can be calculated,and the fluxes were 1. 660 mmol/（m2 · d）,0. 008 mmol/（m2 ·d） and 0. 117 mmol/（m2· d）,respectively. The diffusive fluxes of silicate for CC1,R06,C07 and S23 stations were 3. 101 mmol/（m2 · d）, 1. 660 mmol/（m2· d）, 1. 307 mmol/（m2· d） and 0. 243 mmol/（m2· d）, respectively, which show obvious distribution characteristics with latitude. Distribution of N in the pore water suggested that a strong denitrification process in sedimentary environment of the Chukchi Sea shelf, which is an important sink for nitrate.