Assessment Of Yellow Sea Ecosystem Services

The people enjoy massive services provided by ecosystems consciously or unconsciously. But the provision of services has been threatened by lacking knowledge. The results of United Nation's millennium ecosystem assessment project pointed out that 60% services were using at the degenerate or unsustainable status. To the ocean, this number may be higher.As typical continental shelf marginal sea of the world, Yellow Sea ecosystem and its services were under heavy environment pressures, which from the development of coastal area and the global changes. Assessment of Yellow Sea ecosystem services can provide the real situation of Yellow Sea ecosystem services. Also the assessment can offer the scientific bases for further development.Based upon an in-depth discussion of the theories about marine ecosystem and assessment methods, this paper conducted assessment of Yellow Sea ecosystem services. The historic and present situations of Yellow Sea ecosystem services were analyzed. The present situation of main services was evaluated. By the results, some urgent issues were discussed. And the drivers of these issues were also analyzed. Then, some measures and suggestions were proposed. The main findings of this paper are as follows:1, The theories of marine ecosystem servicesMarine ecosystem services are benefits, which took human as service object, and system itself as material foundation. The benefits were generated by biological components, system itself, and system functions. Besides, realization of the benefits was through marine eco-economic complex system.The production of marine ecosystem services is through 2 sets of approaches. Some services (Recreation, spirit and culture, education and research and habitat) are directly produced from the biological components and (or) system. The others are produced by system functions. The physiological and ecological processes do not produce services directly.Marine ecosystem services have 2 approaches of realization. One is through system itself and system functions directly. The processes of production are also processes of realization. The other is by marine eco-economic complex system. After these services produced, human society and economical system are needed to complete their processes of realization.2, Assessment of Yellow Sea ecosystem servicesAnalyzed results of services quantity show that the services of food production, raw material, and waste treatment were at the high strength use status. And the intensity has the tendency which continues to increase. Results of value analysis show that value of food production, gas regulation and recreation held the ahead three positions of the roll. The sum of these three services value is 82.34% of total value from all services. Compared with assessment result of Sanggou Bay, the values of each services of Yellow Sea ecosystem are 2～6 orders of magnitude higher than Sangou Bay's. Compared with global ocean, each service values of global ocean are 30.51～38357.12 times higher than Yellow Sea's. It shows sketchily that along with enlargement of marine ecosystem scales, value proportions of food production, raw material, and recreation are decreasing; while the proportions of biological control and nutrient cycling are increasing.By the assessment, three significant changes of ecosystem services were found. And these changes need us to pay more attention urgently: First, use intensity and the quantity of food production and raw material were continually increasing. But these increases mainly come from mariculture. Next, the usage of waste treatment was enlarged gradually. However, the quantity increase of this service is far less than use intensity increase. The last, the species diversity of Yellow Sea was threatened seriously.Aimed at the three changes, four main drivers were analyzed, including mariculture, over fishing and bottom trawl, pollution, and reclamation. Then, mechanisms of each driver were analyzed. Interaction and feedback between each driver had also been analyzed. According to these analyses, 12 measures were proposed.