Microbiochemical Studies on the Oxygen Deficient Layer in Inland Fish-farm Water Regions

夏季底质缺氧层的形成是内陆湾养鱼最不利的环境条件之一。为了解决这一问题，本文试图通过与一般富营养化水域相比较，阐明内陆湾养鱼底质有机污染的机理。从两类有机污染水域底质中植物色素、有机碳、有机氮、有机酸、有机质的氨基酸和糖类组成等的垂向分布来看，本研究的结果可以得出以下结论：即使海底的鱼养殖内陆海湾受到来自剩余饵料和鱼类排泄物的高氮含量有机悬浮物的沉重负荷，水域底质的有机污染可通过以下过程进行：1）有机悬浮物在底表面的沉积; 2）水体底表层的分解和矿化; 3）海水的富营养化; 5）植物的生长。6）底质有机污染。

One of the most undesirable environmental conditions infish-culturing inland Bays might be the formation of oxygen deficient layer in bottom water in summer saeason.Toward an aid of the solution of the problem,wetried to elucidate the mechanism of organic polution of bottom sediment in fish-farm inland bays,comparin with that in usual eutrophicated water regions. From the vertical distributions of plant pigments,organic carbon and nitrogen,organic acids,aminoacid and sugar composition of organic substances in the bottom sediment,etc.in the two kinds of organic poluted water regions,the following inference can be drawn from the results obtained in this study.Namely,even though the sea bottom of fish-culturing inland bays are subjected to heavy loads of organic suspended matter with high nitrogen content which is derived from remaining bait and fish excretion,organic polution of the bottom sediment in the water region may proceed by th processes 1) sedimentaion of organic suspended matter on the bottom surface 2) decomposition and mineralization in the water-bottom surface layer 3) eutrophication of sea water j) growth of phytoplanktion 5) sedimentation of dead bodies of phytoplanktion 6) organic polution of bottom sediment.