滆湖地区3种不同鱼类养殖模式的污染强度对比研究

Study on the Pollution of Three Different Aquaculture Modes in Gehu Lake Area

通过对滆湖地区3种不同鱼类养殖模式的污染强度对比研究,结果表明COD在生长旺期的8月达到最高,其中池塘养殖水远高于围栏养殖,达29.3 mg/L。投喂饵料的围栏养殖水COD浓度为16.0 mg/L,也略高于不投喂饵料的围栏养殖水浓度。投饵与不投饵的围栏养殖水体的TN和TP浓度差别不大,在4月浓度最高,分别为4.37～4.68和0.53～0.63 mg/L;池塘水的TN和TP最高值出现在12月的枯水期,分别为5.71和0.73 mg/L。对养殖水体的2次浮游植物群落结构调查表明,7月池塘养殖水质属于中营养化,围栏养殖的2个试验点水质均属于富营养化,12月3个试验点水质均属于富营养化。提高饵料中的营养物质的消化利用率和充分利用天然饵料是控制水产养殖污染的关键。

Through the comparative study on the pollution degree by 3 different kinds of aquaculture modes in Gehu Lake area,it was found that COD reaches the highest level in August.Pond aquaculture COD is the highest of 29.3 mg / L.Fence aquaculture with bait casting is a bit higher than that without bait casting.For fence aquaculture,TN and TP reaches the highest level in April,while those for pond aquaculture reaches the highest level in December.The investigation on phytoplankton community structure shows that in July,fence aquaculture water reaches eutrophication degree,while in December,all of the tested site water reaches eutrophication degree.The key to control aquaculture pollution is by increasing nutrient assimilation rate in the bait and making use of natural aquatic grass.