对虾-罗非鱼-缢蛏封闭式综合养殖的水质研究

研究了对虾、罗非鱼和缢蛏封闭式综合养殖的环境状况.结果表明,混养各组环境状况总体要优于单养组.实验期间混养组DO的波动幅度略小于单养组,最低值则高于单养组;各混养组COD值和水层细菌数量相互差异不显著,但各混养组均显著低于单养组(t检验,α<0.05),混养围隔水体有机质含量明显低于单养;混养各围隔组中浮游生物生物量、Chl.a均低于单养组,滤食性动物对浮游生物的压制作用明显.在底泥中,混养组N、P的积累量比单养组低39.76%和51.26%,混养组细菌总数则比单养组低7.63%.本研究表明,封闭式综合养殖可以大大减少注入近海的养殖污水的排放量,从而降低对近海水质的污染.

Water quality of closed polyculture of penaeid shrimp with tilapia and constricted tagelus

A variety of water quality parameters were monitored in enclosures for the polyculture of penaeid shrimp with tilapia and constricted tagelus.The result showed that the environment of the polyculture systems was better than that of monoculture one. The fluctuation of DO in the water of polyculture enclosures was less violent,and their lowest values were obviously higher than those in monoculture ones.The value of COD and the number of bacteria in the water of polyculture enclosures were significantly lower than those in monoculture ones(t-test,α<0.05),showing that the amount of organic matter in the water of polyculture systems was less than that in monoculture one. The biomass of plankton and the concentration of chlorophyll-a in the polyculture enclosures were also lower,showing that the suppression of the filtering animals to the plankton was obvious.The accumulation of N and P in the sediment of polyculture enclosures was 39.76% and 51.26%,lower than those of monoculture ones, respectively;and the number of bacteria in the sediment was 7.63% lower.Therefore,it is obvious that closed culture system can greatly decrease the effluent to the coastal waters caused by the pond culture industry,and decrease the pollution to the coastal waters.