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

Abstract:

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 is 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 juvenile 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.