海水网箱养殖对沉积环境的影响

海水网箱养殖过程中未被生物摄食的饵料、养殖生物的排泄物及代谢物将对海底沉积环境产生一系列直接或间接的影响。主要污染物包括有机质、化学制剂和营养盐等。沉积物污染会造成溶解氧含量降低、沉积物中硫化物增加以及海底沉积速率增加,导致底栖生物群落发生变化,甚至底栖动物绝迹。部分网箱养殖的污染物质进入沉积环境后在生物、化学和物理作用下释放到海水中,造成二次污染。有些还会通过食物链富集威胁人类健康。

The baits put in, wasted substances and metabolites output have series impacts on the sedimental environment. The main pollution factors include organic matter,chemicals and nutrients. The indirect factors affected axe dissolved oxygen, sulfide and humus piling up on the bottom. The sedimentary pollutants may shift the community structure of benthic organisms and even make them die away. Some of pollutants in sediment may release into the water column again and cause eutrophication and other pollutants can accumulate in sea food chain and threaten human health.