The Impact On The Eutrophication By Aquaculture And The Control Treatment

This paper uses the "Ruttenberg sequential chemical extraction" to study the Phosphorus forms, characteristics and distribution of culture profile Sediment in Junshan Lake, Fushan county and Bishui Garden aquaculture basic. The results show that the form of breeding pond sediment phosphorus content according to the level of regular distribution was as follows:Oc-P> Ca-P> Fe-P> Ex-P> Or-P. In addition to Ca-P, the remainder in the sediment phosphorus profile basically show the increase with sediment depth gradually decreased, and because of the breeding year, all forms of phosphorus content of JSH is less than of FS, especially the most significant form is Ex-P and Or-P. Ex-P, Fe-P, Oc-P and Or-P in Sediments was negatively correlated with the increase of sediment depth, and correlation appears more pronounced when the ponds are in longer years of breeding. Ex-P is directly effected by the pH, temperature and wind, therefore, the content of adsorbed phosphorus is higher in the surface sediment, and is less effected by the external factors in the lower sediment, meanwhile, the content of the lower sediment is gradually stabilizing; Fe-P will change according to the Redox potential of the environment, and slowly release into the upper sediment from the lower sediment, then gradually enriched in the surface layer; Oc-P content is relatively stable, generally difficult to release, but it has greater probability to be effected by impact of human activities in the surface sediment,so it presents that it is slightly lower from the surface to the decrease in the trend. Meanwhile, this paper think that the trend of the change of Ca-P relates to Calcium leached, and leaching is most probably happened in water-soluble calcium and the absorption of calcium. Fushan area has a long-year breeding, and, with the increase of culture year it has been bound phosphorus calcium deposition in the surface sediment, slowly leached, in the contrast, Bishui garden aquaculture basic has less obvious performance of leaching phenomena because the breeding year is short. This paper also make a report about the phosphorus's characteristics of forms in sediments to the total phosphorus via contribution factorial analysis. The result indicated that the adsorption condition phosphorus is the water body total phosphorus most main contribution source, but in the cultivation water body, Or-P,Oc-P,Fe-P are also the water body total phosphorus latent contribution source, while Ca-P does not have the contribution basically to the water body total phosphorus.This paper also make a think to how to control eutrophication, analyzing the TP and the phosphorus content in sediments in water with aquatic plants, indicate that sediment dredging and aquatic plants are the two kinds of methods to controlling eutrophication, point out the advantages and disadvantages brtween the two kinds of methods. This paper's findings and conclusions could have some guidance on the controlling eutrophication of water.