鱼类种群行为及其与环境变化的关系(英文)

Fish Population Behavior and their Relation to the Environment Variations

任何渔业的重要生物特征是鱼类种群的变动。经典的鱼类种群动态模型是以稳定的种群行为为基础的。作者阐述了鱼类种群的行为 ,并划分为三种类型 :(1)稳定型 :种群在较稳定产量上维持较长时间 (反应系数 0 .0 2 )。 (2 )周期型 :种群表现出周期性的高产量和低产量 (反应系数 0 .2 2 )。 (3)不稳定型 :种群产生高产量后无可挽回地崩溃了 (反应系数 0 .3)。在环境变化较大时 ,白色噪音水平 (变动系数 )增加至 35% ,稳定型种群变为不稳定型。在白色噪音水平 (变动系数 )增加至 2 0 %时 ,周期型种群变为不稳定型。

The essential biological feature of any fishery is the dynamics of fish population. The classical fish population dynamic models were largely on the basis of stable population behavior assumption. This paper generalizes the theoretical behavior of fish populations. The fish population behaviors are largely classified into: (1) Steady state. Stocks sustain a more or less steady yield over reasonably long periods of time (responsiveness parameter=0.02). (2) Cyclical. Stocks show periods of high catches regularly followed by periods of low catches(responsiveness parameter= 0.22 ). (3). Spasmodic. Stocks produce major yields and then collapse without any major recovery( responsiveness parameter=0.3). When the environment variations are high, the white noise level(coefficient of variation) increases to 35%, the stable fish population becomes spasmodic. When the white noise level(coefficient of variation) increases to 20%, the cyclical fish population becomes spasmodic.