Assessment Of Ecological Carrying Capacity In Sansha Bay

Sansha bay is located in the northeast of Fujian Province,which is surrounded by the Dongchong peninsula and Jianjiang peninsula.It has a total area of 784km2.It has many harbors and islands which include GuanJingyang,Dongwuyang,Fudingyang,Sanduao.Sansha bay has a vast water area and rich aquatic resources.But the ecosystem of Sansha bay's resources are destroyed by overfishing,water pollution,reclamation and other marine development activities.The marine ecological carrying capacity is the practical application of the ecological carrying capacity theory in the marine field.It is used to research the main problems and causes of marine ecosystem's degradation,and put forward suggestions and methods for the reasons.At present,the research on marine ecological carrying capacity is still at the stage of development,and there is less research on the ecological carrying capacity in Sansha Bay sea area.The research systematically summarized the origin and the development of ecological carrying capacity.Based on the theory of ecological carrying capacity and some selection rules of indicators,the system of evaluation's indicators on marine ecological carrying capacity is designed to hierarchical structure which is divided into 3 layers including target layer,criteria layer and indicator layer.Besides,it confirmed that the indicator's system contained 3 aspects including environment carrying capacity,resource supplying capacity and human supporting capacity with a total of 16 quantitative or qualitative indicators.Moreover,integrating Analytic Hierarchy Process(AHP)with Fuzzy Comprehensive Evaluation(FCE),a set of comprehensive evaluation model is formed and applied to evaluate the ecological carrying capacity of Sansha Bay from 2014 to 2016.The results of the assessment are as follows:From 2014 to 2016,the environmental carrying capacity index of Sansha Bay were higher than 0.5 on average and it showed an increasing trend year by year.In the index,the major stresses of Sansha bay's environment carrying capacity were the excessive amounts of inorganic nitrogen and active phosphorus of water.Although the resource supply capacity of Sansha Bay's ecosystem was improving year by year,it had always been overloaded seriously from 2014 to 2016 because human activities have seriously threatened the sustainable utilization of resources.The human supporting capacity of Sansha Bay had been improving and the grade of evaluation raised but the eutrophication index was at a low level from 2014 to 2016.The evaluation index of Sansha Bay's ecological carrying capacity were higher than 0.5 on average from 2014 to 2016 by its three aspects,weighted summation,but its evaluation index decreased in 2016.However,according to FCE,the maximum grade of membership belonged to "good" has increased.Afterwards,based on the results of evaluation,the main problems of Sansha Bay ecosystem include:1.Exploitation intensity of Sansha Bay sea area is too big;2.Fishery resources are declining;3.Government's public management is not only in the position,but also citizen's environmental protection consciousness is poor;4.The phenomenon of eutrophication is serious.Finally,the research provides scientific and valid restoration's strategies and management's suggestions for the main problems of Sansha Bay ecological carrying capacity.