There were totally 27 different kinds of aquacultural ponds in Songjiang Modern Agricultural Ecological Park. The length and width of every aquacultural pond were 220 m and 50 m, respectively. The breeds cultivated were Penaeus monodon, Macro-brachium species and the Yangtze River crab, among which Penaeus monodon and Macrobrachium species were the main kinds. These two species were cultivated from late May to late September, while the Yangtze River crab was cultivated from late March to late November. Three aeration equipments were put in every pond and were aerated twice every day when the shrimps were young. Theaeration frequency and aeration time were increased as shrimp growing. The aeration frequency in crab pond was less than that in shrimp pond.
Further, the information of feed addition in shrimp ponds was also investigated. We found that the quantity of feed addition was increased as shrimp growing. The shrimp grows very fast especially in August and September. With changes in the time during these periods, the quantity of added feed was largest, and pollution intensity reached the maximum value. It suggests that the wastewater in ponds should be drained off and changed by freshwater at that time. Moreover, the feed addition mainly consists of crude protein. After adding these feed, they flowed to water body mostly in the form of nitrogen, and only about 1% in the form of phosphorus. Besides, the excrement of shrimp and superfluous of feed could also exert a bad influence to water body in aquacultural ponds.