An optimal management strategy for stochastic population dynamics of released <i>Plecoglossus altivelis</i> in rivers

  • Yuta Yaegashi
    Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto City, Kyoto Prefecture, 606-8502, Japan
  • Hidekazu Yoshioka
    Faculty of Life and Environmental Science, Shimane University, Nishikawatsu-cho 1060, Matsue City, Shimane Prefecture, 690-8504, Japan
  • Koichi Unami
    Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto City, Kyoto Prefecture, 606-8502, Japan
  • Masayuki Fujihara
    Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto City, Kyoto Prefecture, 606-8502, Japan

Search this article

Description

<jats:p> 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. </jats:p>

Journal

Citations (12)*help

See more

References(27)*help

See more

Related Projects

See more

Details 詳細情報について

Report a problem

Back to top