For a long term the accumulation of pollutants in the Bohai Sea brings great damage to marine ecosystem, huge economic and social losses. This paper sets up a frame work modeling the optimal path of industrial pollution abatement under tradable permit and seawater cleaning project. Three sub-models are set up which reveal pollution-fish stock interaction, industrial pollution abatement under tradable permit, seawater cleaning project, respectively. Then in next session we introduce dynamic

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... ization problem which combines contains two state equations, which correspond to two state variables fish stock and pollution stock , respectively; four control variables industrial production , volume of pollution abatement , volume of sea water cleaning and catch of fish , respectively. To maximum benefit of fishery, we follow and introduce the optimal solution of four control variables obtained from dynamic optimization.