An optimal management strategy for stochastic population dynamics of released Plecoglossus altivelis in rivers  

作　　者：Yuta Yaegashi Hidekazu Yoshioka Koichi Unami Masayuki Fujihara 

机构地区：[1]Graduate School of Agriculture,Kyoto University Kitashirakawa Oiwake-cho,Sakyo-ku,Kyoto City Kyoto Prefecture,606-8502,Japan [2]Faculty of Life and Environmental Science Shimane University,Nishikawatsu-cho 1060 Matsue City,Shimane Prefecture,690-8504,Japan [3]Graduate School of Agriculture,Kyoto University,Kitashirakawa Oiwake-cho Sakyo-ku,Kyoto City,Kyoto Prefecture,606-8502,Japan

出　　处：《International Journal of Modeling, Simulation, and Scientific Computing》2017年第2期204-219,共16页建模、仿真和科学计算国际期刊（英文）

基　　金：the helpful comments and advice by officers in Hii-River Fishery Cooperatives and Dr.Kayoko Kameda of Lake Biwa Museum.The River Found No.27-1263-020 and No.28-5311-020;JSPS Research Grants No.15H06417 and No.16KT0018;WEC Research Grant No.2016-02,and The Kyoto University Foundation support this research.

摘　　要：Excessive predation pressure from the waterfowl Phalacrocorax carbo(Great Cormorant)on Plecoglossus altivelis(Ayu)has recently been a severe problem of river environment in Japan.Local fishery cooperatives are currently suffering from economic difficulties due to decrease of the fish catch of P.altivelis.Local fishery cooperatives and municipalities have been enthusiastically trying to develop countermeasures that can effectively reduce the predation pressure;however,their effectiveness and efficiency have not been systematically quantified well.This aim can be achieved with the help of an appropriate mathematical model.In this paper,based on a pure death process,a practical stochastic control model for population dynamics of released P.altivelis in river environment under predation pressure from P.carbo,harvesting by human,and environmental fluctuations is proposed.Finding an optimal management strategy ultimately reduces to solving a 2D Hamilton–Jacobi–Bellman equation,which is performed with a finite element scheme.Its application to a Japanese river environment successfully computes the optimal management strategy that is consistent with the reality.Numerical sensitivity analysis of the presented mathematical model is also performed for comprehension of dependence of the optimal strategy on the model parameters.

关 键 词：Optimal fishery resources management inland fishery resources WATERFOWL Hamilton-Jacobi-Bellman equation finite element approximation. 

分 类 号：O17[理学—数学]