基于资源-经济模型的莱州湾中国对虾增殖放流管理

利用2011年莱州湾中国对虾放流回捕生产调查统计和生物学测定数据,构建了包括资源模块、经济模块、决策模块的资源-经济模型,模拟了不同管理决策对放流经济效果的影响.结果表明,放流规模和捕捞强度不变时延迟开捕,总成本降低,渔民捕捞收益和社会经济效益先增加后减少,存在一个使放流经济效益达到最大值的最佳开捕日期：例如,当放流规模为738亿尾、捕捞死亡系数为0.03时,10月8日开捕可以获得最大的社会经济效益19.30万元;放流规模和开捕日期不变时扩大捕捞力量,总成本增加,同样存在一个最优捕捞规模使放流经济效益达到最大,但并非捕捞规模越大获得的经济收益越大;开捕日期和捕捞规模不变时,社会经济效益与放流规模成正比.在放流实践中,管理者应合理设置放流数量、捕捞规模和开捕日期,通过科学管控争取达到最佳的放流效果.

Stock enhancement management of Chinese shrimp Fenneropenaeus chinensis in Laizhou Bay based on resource-economy model

Scientific management decision is of vital importance to improve the economic benefit of stock enhancement.Based on the fishing yield data and biological measurement of shrimp stock enhancement recapture in Laizhou Bay in 2011,we built a resource-economy model which includes resource,economy and decision components for policy simulation.If the opening date for fishing were delayed while the amount of juveniles and vessels were maintained,the total cost would decrease,the fishing income and social-economic benefit would first increase and then decrease,and there is an optimal opening date for fishing to maximize the benefit of enhancement.For example,when 738 million juveniles were released and fishing mortality coefficient was 0.03,the maximum social-economic benefit could be obtained if the opening date for fishing were October 8.If the amount of vessels was increased while the quantity of juveniles and the opening date were maintained,the total cost would increase,but an optimal number of vessel also existed,though more vessels may not mean greater benefit.The social-economic benefit is proportional to the amount of juveniles on the condition of opening date and quantity of fishing vessels unchanged.Management authority should set up reasonable opening date for fishing and optimum amount of juveniles and vessels to achieve the best effect of stock enhancement.