通江湖泊的渔业意义及其资源管理对策

FISHERY SIGNIFICANCE OF THE RIVER-COMMUNICATING LAKES AND STRATEGIES FOR THE MANAGEMENT OF FISH RESOURCES

长江中、下游的江湖复合生态系统包含有河流和湖泊两个环境单元。其中的鱼类群落由河海洄游鱼类、江湖洄游鱼类、河流鱼类和定居性鱼类等４个生态类群组成，尤以江湖徊游鱼类对这一特殊的生态环境形成了良好的适应，因而种群数量繁盛。从渔业的角度看，水利工程造成的江湖阻隔削弱了通江湖泊的生态功能，成为导致鱼类资源下降和种类结构改变的主要原因之一。当前应从控制捕捞、人工增殖和恢复生态环境结构等方面着手进行资源管理，确保鱼类资源的永续利用。

Channels and their associated lakes in the middle and lower reaches of the Yangtze Riverformed a compound river-lake ecosystem. The fish assemblages inhabiting there can be divided into four ecological groups, i. e., river-sea migratory, river-lake migratory, potamophilous andlimnicolous. Especially, the river-lake migratory fishes were dominating over foe fish outputs because they had adapted themselves to the special environment morphologically and ecologically.Due to the blockages of river-Jake communicstion caused by the constructions of hydraulic projects, the integrity of the river-lake ecosystem was destroyed, and the fishery productions and theamount of river-lake migratory fishes have both shown a continuous decline here. No doubt thedestruction of the function of those associated lakes was one of the main reasons which brought thedecrease in fish resources and the alternation in species-structure of fish assemblages. Thus, tocontrol overfishing, to stock the lakes artificially and to restore the eec-environmental pattern arethe essentials to the management and the sustainable utilization of fish resources.