Analysis And Assessment On The Characteristics Of Eutrophication In The Xiamen Bay And Its Adjacent Coastal Waters

Coastal Eutrophicationis a prominent environment problem of marine ecologicalwhich impacts economic and social sustainable development in China, with theinterdisciplinary typically. This paper selected the Xiamen Bay and its adjacent seaarea as the research object, with reference to international mainstream of the PhaseⅡ eutrophication assessment methods, built an integrated and suitable methodologyfor assessment of the study area, in order to facilitate the Marine ManagementDepartment to monitor and manage the study eutrophication area in real-time. At thesame time, compared with the NOWPAP eutrophication evaluation system tooptimize the evaluation method. Through the research, the main conclusions obtainedin this paper are as follows:(1) During the2013survey, the average content of DIN in Xiamen study seaarea were inferior to the forth class of sea water quality standard except the averagecontent of August. The average content of DIP in August were accorded with the firstclass standard, other sea area waters were inferior to the forth standard. The averagecontent of COD and DO in the Xiamen sea area were accorded with the first class ofsea water quality standard. The average content of Chla were higher in August thanany other months.(2) In the recent30years, the change trend of average DIP and DINconcentration in Xiamen sea area increased in varying degrees,compared with theend of the20th, the average content of DIN in West sea, Jiulong river estuary, East seaand Tongan bay were increased by2.98times,4.54times,1.57times, and4.29times;the average content of DIP were increased by2.07times,1.71times,1.31times and3.00times.(3) Application of the eutrophication assessment method which was built in thispaper to analysis and evaluate the eutrophic state of Xiamen Bay and its adjacent seawaters. The evaluation results show that: the integrated eutrophic grade of Xiamencoastal waters has been classified as moderate(2－3－3), the rate of pressure was highmoderate, the degree of status and response were moderate. (4) Application of the NOWPAPcomprehensive eutrophication assessmentmethod to research the study area in the paper. The evaluation results show that: theevaluationresults of four index rating in West area were HI, HD, LN, LN; theevaluationresults of four index rating in Jiulong river estuary were HI, LN, LN, LN;the evaluationresults of four index rating in Tongan bay were HN, HI, LN, LN; theevaluationresults of four index rating in South area were HD, LN, LN, LN; theevaluationresults of four index rating in East area were HN, LI, LN, LN; theevaluationresults of four index rating in Dadeng area were LN, LN, LN, LN.