Abstract: In this paper, the dynamic behavior and optimal harvesting policy for a class of inshore-offshore fishery model are investigated. In the model, the inshore fish is caught by proportional harvesting and constant harvesting simultaneously, and the inshore fish and offshore fish diffuse with each other continuously. Objective functional is to obtain the maximal profit which is the difference between economic revenue and cost. The optimal control policy is obtained through applying the Pontryagin maximum principle and some analytic skills. The exact expressions of  optimization policy and the economic profit are given.

Key words: inshore-offshore fishery system, continuous diffusion, Pontryagin maximum principle, optimal harvesting policy, maximum economic revenue

摘要： 研究一类同时具有比例收获和常量收获的近远海渔业系统的动力学行为和优化控制问题。在种群发展中近海鱼群和远海鱼群进行连续迁徙扩散，为了使得一个收获周期内有最大的经济净收益，应该研究制定合理的收获策略。利用Pontryagin极值原理和一些分析技巧，获得了最优收获策略，得到了收益的具体表达式。

关键词: 近远海渔业系统, 连续迁徙扩散, Pontryagin极值原理, 最优收获策略, 最大经济利润