湖泊渔业可持续发展的生态学基础及一个范例

从渔业与环境兼顾的角度出发作者认为湖泊渔业可持续发展的生态学理论基础是渔业生态学和渔业湖沼学. 前者是一门较为成熟的学科研究渔业对象的种群生态学渔产潜力最佳放流密度和规格以及科学的捕捞策略等. 后者研究渔业对湖泊生态系统生物多样性和水质的影响并确定最佳的渔业规模和渔业方式但尚未提出令人满意的理论和完善的实验方法今后应予充分重视. 长江中下游草型湖泊因为其优良的水资源和丰富的生物资源而成为我国内陆水体发展优质高效渔业的重要基地. 以湖北一个浅水草型扁担塘渔业实践为例作者着重强调生态学管理的如下方面1) 沉水植被是草型湖泊优质高效渔业持续发展的基础必须在合理利用的同时加以保护优化甚至重建使生物量和覆盖率保持和达到一定水平. 2) 食物链网的基础环节是渔业对象生长和繁衍的物质基础, 必须进行培育保护以提高其生产力从而为提高渔业产量打下物质基础. 3) 合理放养与捕捞策略是湖泊渔业生态系统良性循环的可靠保证应使高价值的种群规模保持较大水平的输出.

Ecological Theories for Sustainable Fishery in Lakes

The ecological theories for sustainable fishery of freshwater lakes are fisheries ecology and fisheries limnology. Fisheries ecology focuses on biology of fishery species, potential production, optimal stocking density and size, rational input of subsidy energy, and rational catch strategy, and so on. Fisheries limnology researches the stress of fishery on the freshwater resource and biodiversity in lake ecosystems, which can define fishery size and fishery model. The macrophytic lakes along the mid-lower reaches of Yangtze River become the main freshwater fishery base with high quality and high efficiency in China in recent years because of its good water quality and rich bioresource. When some high-market-price species, such as Eriocheir sinensis and Siniperca chuatsi, are stocked as main fishery species, ecological management is very important. The authors emphasize the following three aspects: 1. The submerged macrophyte community, which is the basic and key factor of sustainable fishery, must be used rationally, protected carefully and rationalized for fishery. When the community collapses, restoration is necessary. 2. The basic links of food chainswebsmust be protected to raise their biomass and production for fishery species. 3. Good strategies of stocking and catching are also very important for fishery ecosystem.