The discharge state of major pollutants around Yueqing Bay

Eutrophication, characterized by nitrogen (N) and phosphorus (P) material, has become the major factors influencing both Zhejiang nearshore and Yangze River Delta Area. Yueqing Bay of southeast Zhejiang is taken as an example to analyze its major pollutants. Survey and quantitatively analysis of the pollution sources in the catchment of this bay was conducted. The results show that CODcr mainly came from mariculture, land-based pollution is secondary in 2012. Nitrogen(N) and phosphorus(P) mainly caused by land-based pollution, accounting for 83% and 80% for the total nitrogen(TN) and total phosphorus(TP) respectively. Taking the investigation results in 2005 into account, by analyzing the impact on Yueqing Bay from human activities and its trends in the future, the conclusion and improvement suggestions are summarized.