Water pollution of Yellow River estuary coastal wetland

14 representative water-sample sites were selected around the coastal wetland of Yellow River Estuary and three times surveys were carried out on May(dry period),August(wet period) and November(level period),respectively.22 pollution indexes such as nutritive salt,heavy metal,petroleum etc.were measured.The pollution status was assessed with Nemero Index and comprehensive nutritional status index(TLI).The results showed that the water quality of coastal wetland was light eutrophication and deteriorated with each passing year.The slight pollution sites were found at wetland lakes,Yellow River old course,the national nature reserve,culture ponds and other static state water area,whereas the tributaries like Guangli River,Tiao River,Shenxiangou River,Xiaodao River and Gudong oil fields drainage ditch were serious polluted which were more serious polluted than the Yellow River.TN,TP,NH4+-N,UIA,Chl-a and petroleum were main pollutants at coastal wetland.As for the pollution of nitrogen and phosphorus,comparing with historical data,deteriorated significantly.The whole water quality was not optimistic in Yellow River estuary,although no significantly increase of petroleum pollutants and Hg pollution and no detection of other heavy metals.