东海带鱼种群动态管理与最优化开发策略

DYNAMICS MANAGEMENT OF THE HAIRTAIL TRICH1URUS JAPONICUS (PISCES, TRICHIURIDAE) STOCKS IN THE EAST CHINA SEA AND THE STUDY OF ITS OPTIMAL HARVESTING STRATEGIES

根据1960—1986年东海带鱼春夏汛和冬汛资料,提出了均匀渔捞死亡假设,推导出种群状态更新方程式,并应用状态变量法建立了东海带鱼的随机动态系统模型;在此基础上以随机动态规划理论计算了东海带鱼资源在不稳定补充条件下的最优化开发率和限额捕捞量,并模拟预测了带鱼最优化策略的效应。

The data used for the present paper were obtained in the years 1960 - 1986 rom the spawning ground and wintering ground in the East China Sea. A new-fstate-update equation for fish stock with the presupposition of even fishing morta lity is derived:N(t+T)=N(t)·exp(-MT)-Ct1-exp(-MT)/MTOn this basis, a stochastic dynamic system model of the hairtail in the East China Sea has been set up by means of state variable:N(k+1)=f[N(k),Cs(k),Cw(k),α(k)]The dynamic optimal exploration rates and yields for both spring-summer and winter seasons have been calculated by means of principles of stochastic programming in the case of unstable recruitment. Finally, Monte Carlo method is adopted for ismulating and forecasting the population dynamics of the hairtail in the East China Sea under exploration by optimal harvesting strategies on a computer. The studies have shown that an average annual yield of 42×104 tons could be obtained from the dynamic fishery management.