长江流域水资源开发保护中的关键科学和技术问题

长江是我国鱼类多样性最高的河流，同时也是我国最重要的淡水渔业资源产区。然而，近几十年来受水域污染、水工程建设、湖泊围垦、航运发展、过度捕捞和外来种入侵等多重因素的影响，长江流域生态系统面临着逐渐衰退的困境，主要表现为鱼类种类数减少、鱼类濒危物种程度加剧、鱼类资源小型化趋势明显、鱼类资源呈衰退趋势和外来物种种类增多等。长江十年禁渔，对恢复长江水生态环境和保护水域生物多样性提供了重要的机遇。作者建议统筹协调长江生态保护与渔业发展的关系，创新流域管理体制与机制，根据长江水生态系统结构与功能变化，适时调整服务目标，其目的旨在实现对长江流域水生态环境的保护和渔业资源的可持续发展提供科学依据。

Key scientific and technological issues in water resources exploitation and protection in the Yangtze River Basin

The Yangtze River is the longest river in China, stretching 6300 km and playing an irreplaceable role in the country's ecosystem. It is also home to one of the world's richest aquatic biodiversity, with 443 freshwater fish species and 156 of them being endemic to the river. As a major source of freshwater fishery production in China, the capture fishery yield accounts for 60% of the total Chinese inland fisheries output. However, human activities such as hydro project construction, enclosing-lake cultivation, overfishing, water pollution, shipping development, and exotic fish species invasion have caused a declined aquatic ecosystem service of the Yangtze River ecosystem. This decline is reflected in the decrease in fish species, increase in endangered species, miniaturization of fish individuals, and increase of exotic species. To resolve this issue, the Chinese government has implemented a ten-year fishing ban in the Yangtze River, starting on January 1, 2021, with the aim of restoring the aquatic environment and conserving the aquatic biodiversity. To ensure the sustainable development of fishery resources in the Yangtze River, it is suggested to coordinate the relationship between ecological protection and fishery development, innovate the management system and mechanism, and adjust service objectives according to changes in the Yangtze River aquatic ecosystem. These studies aim to provide a scientific policy suggestion for the protection of the Yangtze River aquatic ecosystem and the sustainable development of its fishery resources.