中文摘要：

以Logistic模型为基础，考虑捕捞行为及其所造成的污染对浮游生物的削弱作用，并考虑浮游生态系统具有一定的自净能力，建立了一个新的海洋浮游生态系统非线性动力学模型。分析了模型的非线性动力学特性，并得出了模型的稳定性条件和发生Hopf分岔条件，在此基础上，深入分析了捕捞强度参数的变化对系统稳态的影响，并且用数值模拟验证了理论分析结果的正确性。

英文摘要：

A new nonlinear dynamical model of marine planktonic ecosystem which is based on Logistic model is proposed. The weakening effect to the plankton which is caused by catching and pollution and the self-purification capacity of the marine planktonic ecosystem are both considered in this model. After analyzing the nonlinear dynamical property of the model, the conditions of stability and the Hopfbifurcation of the model are obtained. Further more, the influence of catching intensity parameter changes on marine planktonic ecosystem＇s stability is studied and the correctness of the theoretical analysis is proved by the results of numerical simulation.