Establishment of integrated methodology for bay ecosystem health assessment and its application in Daya Bay

Abstract

Bay ecosystem health, recently, has faced a growing interference and disturbance by anthropogenic activities, which has also caused challenges to ecosystem management. Ecosystem health assessment, a new methodology of ecosystem assessment, could obtain the current situation both of ecosystem structure and function and provide a great of necessary information for ecosystem management. An integrated assessment methodology for bay ecosystem health was established based on geographical information system ( GIS) technology, which was on basis of a " pressure鄄structure鄄response冶 frame model for marine ecosystem and an ecosystem health assessment indicator system constructed by external pressure, ecosystem structure and response parameters. This paper also presented a case study of Daya bay in spring by employing GIS technology.The results showed that the average ecosystem health integrated index was 0. 57 in Daya Bay ecosystem in spring.Detailedly, organic pollutant index ranged from 0. 36 to 1, with the average value at 0. 87, was at " very good冶 level of Daya Bay ecosystem. Eutrophic level index value ranged from 0. 17 to 1, with the average of 0郾 77, indicated " better冶 level of the ecosystem. Furthermore, phytoplankton abundance index was at a " worse冶 level because of the ranges from 0. 33 to 1 and the average of 0. 21. Zooplankton biomass index ranged from 0. 16 to 1, with the average of 0. 88, suggested the ecosystem was at a " very good冶 level. Zoobenthos biomass index was at " critical state冶 , as the index value ranged from 0