台湾海峡西部海域表层沉积物氧化-还原环境探讨

ON THE OXIDATION-REDUCTION ENVIRONMENT OF SUR-FACE SEDIMENT IN WEST AREA OF TAIWAN STRAIT

本文根据1984—1985年国家海洋局第三海洋研究所对台湾海峡西部海域环境进行多学科综合调查的沉积化学和底栖生物的资料,概述了该海区表层沉积物的有机质、Eh、Fe^(3+)/Fe^(2+)分布特征。把该海区沉积物氧化-还原环境区划分为三种类型:较强氧化区;弱氧化区;弱还原区。发现本区底栖生物在这三个区的分布差异是:弱氧化区最高;较强氧化区次之;弱还原区最低。

This article shows the distributive characteristics of oxidation-reduction environment indexes such as organic materials, Fe3+/Fe2+ and Eh on surface sediment in the west area of the Taiwan Strait. The change range for organic materials was 0.06-1.32% (average was 0.37%) and tended to be higher in the north, lower in the south, higher in the area near to, and lower'in the area far from the coast. Fe3+/Fe2+ ranged from 0.37-31.67 (average was 4.89). Eh ranged from 17-369mV (average was 221mV) and tended to be higher in the south and lower in the north, decreasing westward. The above distributive patterns had some relationship with the sediment types. The small sized particles had more organic materials, lower Fe3+/ Pe2+ and Eh; the large particles had opposite trend.Based on the organic materials, Fe3+/Fe2+ and Eh, the area was divided into three regions of oxidation-reduction environment: Ⅰ. stronger oxidation region; Ⅱ. weaker oxidation region; Ⅲ. weaker reduction region.The different oxidation-reduction environments in sediment affected the population and species number of benthic organisms. The biomass and population density of the main benthic organisms (Echinoderm, Polychaeta) in the area were the highest in the weaker oxidation region, the second highest in the stronger oxidation region, the lowest in the weaker reduction region. This showed that the weaker oxidation region of the area is suitable for Echinoderm and Polychaeta growth. The total biomass of benthic foraminifera is the highest in the weaker reduction region.