Study On The Pollution Load Calculation And Polluting Effect Of Barier Net Aquiculture In Yangcheng Lake

Be of far reaching importance to research the problem of aquiculture pollution anddiscuss the effect on the aquatic environment brought by freshwater ecologicaquiculture, so that gain the maximal benefit between the environment and economy,which is also good to do the development planning of fishery advance, reduce thewater contamination more, control the eutrophication of water area and preserve theupstanding water.This paper investigated into the problem of aquatic environment in Yangcheng lakecaused by aquiculture of river crab, worked out the pollution load (primarily the N,Pload) of the river crab aquiculture in Yangcheng lake by means of experiment andmodeling. The reasonable culture capacity and acreage are advised. It discussed thefresh water aquaculture how deeply acted on the environment under the presentmanage and running pattern, which include the effect of aquatic environment andecological environment caused by emission of culture waste, and raised the relevantapproach.The resolution of the study displayed:(1)The water quality in aquiculture period is worse than in non aquicultureperiod(mainly the TN), and there is bad effect on aquatic environment.(2)In the researching period, the total N/P of each monitoring point in east lake wereall greater than 16, this indicated the lake is short of phosphor, and are took P as thelimiting factor of plankton growth. Because a great deal of bait were put into thewater during the process of aquiculture, the phosphor was increased in the water, andfor the sedimentation and resuspension of the rest bait, the concentration of inorganicphosphorus increased in water, that means there is the tendency to polyphosphateduring the aquiculture. Besides, there is a trend that TN/TP is going to lower incompany with the aquatic time.(3) During the process of aquiculture, the bait or the metabolite of organism dissolvedin the water partly, and after they sediment on the mud partly, which released into thewater by the action of biochemistry. The content of TN,TP of mud in relation to a lot of element, include the demand of bait for crab, the releasing amount of mud, thetemperature, and the condition of hydrodynamic force etc.(4)The model of pollution load estimate on TN,TP of barier net culture in Yangchenglake was built, then it figured out the TN load (67060.45kg) and the TP load(4948.323kg) which brought by barier net culture annually. This study indicate thatthe barier net culture have brought some pollution, which is mainly because the TNload are too much.(5)This study choose the TP load as guideposts to estimate the culture capacity ofbarier net. It has calculated that the maximum acreage of barier net culture is 6234mou, and it need the theoretic amount of ground bait about 18023.1t/a for theproduction of 1451.6t/a.(6)The countermeasure of aquiculture contamination control mainly concludes: createthe health aquiculture pattern; carry out the cleaning production of aquiculture;enhance the research of processing the discharge water of aquiculture; draw theenvironmental standard of aquiculture; and rehab the entironment of the aquiculturewater.