Simulation of red tide formation in semi-enclosed coastal sea and its application for prevention

本研究选择埃田岛湾作为濑户内海典型的半封闭近岸海调查对象。为了建立数学生态模型，对大气参数、水质和浮游生物初级产量进行了观测。采用实时监测系统和中生态系统进行观测，测量水温、盐度、溶解氧、氢势、叶绿素a、营养物质、浮游生物数量。中尺度观测评价了水流水平输送的影响。数学生态模型由溶解氧、溶解无机磷、悬浮生物、溶解生物和盐度、水温等辅助参数组成。在普林斯顿海洋模型的基础上，建立了一个海洋模型来模拟埃塔岛湾中牡蛎筏的影响。本研究采用海洋模式、大气模式和数学生态模式相结合的方法开发了环境生态系统模拟器。发达的环境生态系统模拟器揭示了牡蛎对生态系统的影响，启发了通过设置牡蛎筏控制生态系统和赤潮形成的可能性。

In the present research, Eta-jima Bay was selected for the investigation of the typical semi-enclosed coastal sea in the Seto Inland sea. The atmospheric parameter, water quality and primary production of plankton were observed for the establishment of the mathematical ecological model. Real time monitoring system and mesocosm were employed for the observation in which water temperature, salinity dissolved oxygen, potential of hydrogen, chlorophyll a, nutrients, number of plankton were measured. The observation by the mesocosm evaluated the effect of the horizontal transportation by current. The mathematical ecological model was composed by dissolved oxygen, dissolved inorganic phosphorus, suspended organism, dissolved organism with subsidiary parameter as salinity and water temperature. Ocean model was developed to simulate a current based on the Princeton Ocean Model including the effect of oyster raft which occupy in the Eta-jima bay. In the present research, environment ecosystem simulator was developed by the combination of the ocean model, atmosphere model and mathematical ecological model. The developed environment ecosystem simulator revealed the effect of the oyster on the ecosystem, which inspire the possibility to control the ecosystem and red tide formation by the arrangement of the oyster raft.