大渡河金川至丹巴河段干、支流鱼类资源及其多样性分布

为进一步了解大渡河金川至丹巴河段干、支流鱼类群落结构及其多样性分布特征，2020年5和9月、2021年5和7月对大渡河上游金川电站坝址至猴子岩电站库尾108km干流及区间主要支流进行了系统的鱼类资源调查与分析。结果显示：研究河段共分布有鱼类19种，隶属3目6科11属；鲤形目种类最多（15种），占总种数的78.95%；鲇形目（3种），占15.79%，鲑形目（1种），占5.26%。土著鱼类（14种）主要为裂腹鱼亚科、高原鳅属和爬鮡属等适应高山峡谷流水生境、特化程度较高的鱼类。其中，大渡河裸裂尻鱼（Schizopygopsis chengi chengi）、细尾高原鳅（Triplophysa stenura）和齐口裂腹鱼（Schizothorax prenanti）为研究河段的优势种。渔获物统计及多样性分析表明，干流与小金川、革什扎河、东谷河及勒乌沟等支流土著鱼类组成较为相似，但干流与支流以及各支流间鱼类资源及其多样性差异明显。研究表明，本河段鱼类群落组成简单，生态脆弱性较高，种群资源一旦遭到破坏，将很难恢复。且大部分土著鱼类为珍稀濒危和特有鱼类，保护意义重大。同时，大渡河上游鱼类正面临严重的外来鱼类入侵威胁，需引起高度关注。研究结果可为梯级开发对鱼类资源的影响评估提供基础资料，为鱼类栖息地保护等水生态保护措施的规划和设计提供依据。

Fish Resources and Diversity in the Mainstem and Tributaries of Dadu River from Jinchuan to Danba

Surveys on fish resources were conducted at 22 sampling sites in May and September 2020, and May and July 2021 to further understand the fish community structure and diversity distribution characteristics in the main and tributaries from Jinchuan to Danba reaches of the Dadu River. A total of 19 species were identified belonging to 3 orders, 6 families and 11 genera. Indigenous fish were highly specialized, and adapted to alpine valley running water habitat, including Schizothoracinae, Triplophysa and Euchiloglanis species. Schizopygopsis chengi Chengi, Triplophysa stenura and Schizothorax prenanti are the dominant species in the research area. The catch statistics and diversity index showed that the fish compositions in main stream was similar with the tributaries such as Xiaojinchuan River, Geshiza River, Donggu River and Lewugou River, but there were significant differences in fish resources and diversity between the main stream and tributaries, and among tributaries. The results suggested that the fish community structure in the main and tributaries from Jinchuan to Danba reaches of the Dadu Rive was simple, and ecological vulnerability was high. Once the fish resources were destroyed, it would be difficult to recover. Most of the indigenous fish are rare, endangered and endemic, and have high conservation value. Meanwhile, the fish in the upper reaches of the Dadu River are facing a serious threat of alien fish invasion, which needs to be paid close attention. The results will provide basic data for assessment of the impact of cascade development on fish resources, and provide a basis for planning and designing aquatic ecological protection measures such as fish habitat protection.