3.1.2. Water quality of aquacultural ponds
Two different kinds of shrimp ponds and one crab pond were selected as representative to investigate water quality of aquacultural ponds. The average value of water quality is shown in Table 1during the experimental period. It was found that most of the water quality index, including CODCr, TN, NH4+-N and NO3—N were very high. The high load of aquaculture l wastewater was confluence to Huangpu River (regarded as the mother river of Shanghai city) ,which could reduce biodiversity of water body and cause eutrophication. Thus, it is necessary to strengthen the wastewater treatmentof aquacultural water in this area.