Organic Phosphorus Contents,Total Organic Carbon,Total Nitrogen and Their Isotopic Characteristics from Sediments in Jiangsu Coast,China and Source Identification of Organic Matter
The distribution and source of sediment organic matter are a key and difficult issue in the studies of the sea-land transition biogeochemical cycle and coastal ecological environments,and have been widely concerned.The Jiangsu coast was chosen as a study area,61 surface sediment samples were collected in 2016,the organic phosphorus(OP)contents,total organic carbon(TOC),total nitrogen(TN),and the isotopic compositions of organic carbon and total nitrogen(δ13Corg,δ15Nto,values)were investigated to identify the sources of organic matter from sediments in Jiangsu coast.The results show that the significant correlations between OP contents,TOC,and TN in sediments and particle sizes,which are significantly influenced by the hydrodynamic effects.The qualitative analysis of the element ratios and isotopes show that the sediment organic matter is mainly provided by marine organisms and is also supplied by terrestrial inputs to some extent.The calculated results of the isotope mixing model further find that the contribution proportion of the marine source to sediment organic matter of Jiangsu coast is averagely 56.9％,followed by terrestrial C3 plants,soil,and agricultural fertilizers with an average contribution proportion of 38.5％,and domestic sewage contributes only 4.6％.Marine organic matter is transported to Jiangsu coast through oceanic currents and tidal waves,and river input and coastal aquaculture might be important patterns of terrestrial input.Terrestrial input is not the main contributor to the organic matter of sediments in Jiangsu coast,but is probably a driving factor for coastal eutrophication.The findings are helpful in deeply understanding the biogeochemistry cycle in the land-sea transition zone,and provide a theoretical guidance for the prevention and control of coastal organic pollution.
万方数据
维普
