Bull. Jpn. Soc. Fish. Oceanogr. 81(3), Page 203-210, 2017   Development of fish population dynamics model including characteristic of environmental response in coastal sea area: application to Ammodytes personatus sp in Osaka Bay as an example Yohei Tsukahara1†, Fumika Shishido1, Qin Yuqiong1 and Naoki Nakatani1 1 Graduate school of Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan † E-mail: tsukahara_y@affrc.go.jp The coastal sea area affected by both outer sea and land area has had a variable environmental state. Additionally, influences of human economic activities make it more complicated. Analyzing using a numerical model is an effective way to figure out the relationship between the fluctuation of the environmental state and fish population dynamics quantitatively. On the other hand, there has not been enough ecological knowledge to develop a numerical model. The purpose of this study is to develop a numerical model using statistics. This model is applied to Ammodytes personatus sp in Osaka Bay as an example. Apparently, non-linear responses of fish population to environmental factors are revealed by optimal transformation method and are formulated as a population dynamics model, including environmental effects based on the responses. Additionally, MCMC method is used to estimate optimal parameters for many unknown parameters in the developed model. These results allow the quantitative evaluation of the imact of fisheries and the environmental state on fish population dynamics of Ammodytes personatus sp in Osaka Bay. Key words: MCMC method, Ammodytes personatus, Population dynamics model, Optimal transformation method