河口及近岸海域低氧环境对水生动物的影响

A review on the effects of hypoxia on aquatic animals in estuaries

水体溶解氧浓度低于2 mg/L时,通常称水体为低氧或缺氧(hypoxia)。目前,中国的长江口等许多河口及近岸海域的底层水体出现了季节性低氧区,这些低氧区对鱼类等水生动物及海洋生态环境的影响目前仍不十分清楚,这应引起政府及研究部门的关注。本文综述了低氧区的成因,分析了低氧对水生动物的影响,特别是近年来研究较多的水生动物对低氧的分子响应研究进展,最后综述了低氧对海洋生态系统的影响。我国未来的研究应注重低氧区海洋物理、海洋生物等基础数据的收集,同时,要加强低氧区对我国主要渔场影响的研究。

Hypoxia is defined as dissolved oxygen less than 2 mg/L in the water. In recent years, due to excessive anthropogenic input of nutrients, organic matters, and global warming, hypoxia zones have been expanding year by year all over the world. Hypoxia has threatened the survival of marine animals, destroyed marine ecosystem and reduced fishing production. In this paper, we analyzed the causes of hypoxia and its＇ effects on marine animals and ecosystem. Hypoxia mainly results from the accumulative oxygen consumption of organism and density stratification of the water column, which restricts water exchange and oxygen supply. However, in more cases hypoxia is due to excessive anthropogenic input of nutrients and organic matters into water bodies where there is poor circulation. This paper also reviewed the effects of hypoxia on marine animals. Hypoxia affects survival, aquatic animals. the structure of Hypoxia changes food chain and growth, reproduction, behavior, physiology and some gene expression of the composition and structure of marine benthic community, and also alters energy flow of marine ecosystem. Finally, we prospected the research development tendency.