Study on temporal and spatial distribution of nutrients andeutrophication in the seawater of Jiaozhou Bay wetland

Based on the environmental data surveyed in February,March,July,August,September and November,2009,the temporal and spatial distribution of nutrients and eutrophication level in the seawater of Jiaozhou Bay wetland were studied. It was found that:(1) The regions with higher content of DIN and DIP in the seawater of Jiaozhou Bay wetland were roughly located at the estuary of Dagu River and its adjacent waters,and the horizontal distribution of them were mainly controlled by runoff amount of fresh water.(2) There were apparent seasonal variations of DIN and DIP content in the seawater of Jiaozhou Bay wetland.Basically,their contents were positively related to the input of fresh water,i.e.,the nutrient content was higher in the higher flow period and lower in the lower flow period.(3) The eutrophication level of seawater was higher in Jiaozhou Bay wetland,belonging to potential eutrophication with medium phosphorous limiting.(4) Organic pollution was more serious in the seawater of Jiaozhou Bay wetland,belonging to moderate pollution level.(5) The Dagu River runoff was the main source of nutritional substances such as nitrogen,phosphorous etc.Too much nitrogen and phosphorous in the seawater had caused the eutrophication.Effective measures should be adopted to solve this striking environmental problem.