Abstract:

According to the spot investigation and the experimental analysis of fish cagefarming in the confluence of Badong Guandu,results demonstrated that the water quality of cagefarming area was inferior to the control cross section,and control cross section was inferior to the background and cross section.The water quality of different sampling stations on the same cross section was immovable basically.However,the water quality of controls in cross section was gradually improved as far from cagefarming area.According to the principal components analytic method,the influences of different fish cagefarming area on the water quality are as follows:the sturgeon cultivation area>American paddlefish cultivation area>the yellow catfish cultivation area>the carp and the grass carp cultivation area.The correlation analysis of various water qualities parameters indicated that diversities and abundance of algae in Badong Guandu had high relativities to the total phosphorus and the ammonia nitrogen respectively;the parameters of ammonia nitrogen,total nitrogen,total phosphorus and permanganate index obvious related one to another,which indicated that the source of pollution had high homology and the water pollution was mainly ascribed to the fish cagefarming.In this paper,exceeded background concentration of 5% was used as the standard for background pollution zone,the exceeded background pollution area of ammonia nitrogen and permanganate index was about 10 times and 5 times than fish cagefarming area respectively