Performance Evaluation Of Fishing Ban In Shenzhen Bay Based On Analytic Hierarchy Process(AHP)

Marine economy plays an important role in social and economic development in China.In recent years,the fishery resources of marine ecosystems around the world have been declining,especially in coastal ecosystems.Overfishing has been regarded as one of the main factors that influence the fishery resources sustainable development.Overfishing causes a mismatch between predator and prey,degradation and decline of fishery population,and decreases of population structure stability.With the dramatic growth of population and the rapid development of economy,the impact intensity of human activities on the coastal environment is gradually increasing,marine environment was somehow contaminated and habitat for marine animels was destructed.Taking Shenzhen Bay as an example,the environmental index,ecological index and fishery resources index were selected to construct the evaluation index system of fishing ban.On the basis of the expert opinions and field surveys of the Shenzhen Bay,twenty-two representative indicators were determined,and the relative importance and weight value of each indicator were determined by using the analytic hierarchy process(AHP).Based on the survey data of 2013 and 2017,this evaluation system was used to calculate the comprehensive evaluation index,compare and evaluate the performance of fishing ban in both temporal and spatial dimension.The comprehensive evaluation index of restricted fishing areas in 2013 and 2017 were 0.518 and 1.104,respectively.Furthermore,the comprehensive evaluation index of non-restricted fishing areas was 0.551 in 2017.The fishing ban policy increased the resource density and fishing rate of fish,crustaceans and cephalopods,and also increased the abundance of phytoplankton,the resource density of zooplankton,benthic organisms,fish eggs and larvae.The situation of fishery resources had been greatly improved.The results indicated that the fishing ban policy had achieved positive and significant effects in both spatial and temporal dimensions.The establishment of the restricted fishing areas protected the local ecological environment and provided sufficient time and space for the growth and reproduction of organisms.