大渡河上游鱼类资源现状

2017-2019年,对大渡河上游鱼类种类组成、优势种和多样性指数等进行了调查。结果显示:大渡河上游采集到鱼类2目6科24种,其中包括了四川省级保护鱼类2种、长江上游特有鱼类8种以及外来物种3种。大渡河上游现有分布鱼类以齐口裂腹鱼(Schizothorax prenanti)和重口裂腹鱼(S.davidi)等为优势种群,生态类群以杂食性、底层、冷水性为主;鱼类种类数、Shannon-Weiner多样性指数、Margalef物种丰富度指数和Pielou均匀度指数均表现为泸定电站库区最高。结果表明大渡河上游鱼类区系组成简单,属典型的青藏高原类群,但受梯级电站的开发、肆意地人工放生活动等影响,鱼类资源呈现衰退趋势,外来鱼类入侵现象严重。

Analysis of fish resources status in the upper reaches of the Dadu River

Surveys on fishery resources were conducted at six sampling stations from 2017 to 2019 in order to understand the fish resource status and diversity index in the upper reaches of the Dadu River.A total of 24 species were identified inside 2 orders,6 families,and 53 genera.Among these species,2 species were enlisted as protected species in Sichuan Province,8 species were endemic to the upper Yangtze River and 3 species were non-native fish in the upper reaches of the Dadu River.The analysis of catch showed that Schizothorax prenanti and Schizothorax davidi were the most dominant,and the primarily ecological types were the omnivorous,benthic and cold-water fishes.The number of fish species,Shannon-Wiener diversity index,Margalef index,Pielou index values of Luding reservoir were the highest.The results suggested that the species composition in the upper reaches of the Dadu River was simple,which belonged to typical Tibetan plateau taxa.Due to hydraulic power plants constructions and irregularities fishery release,fishes resources are declining and the invisive species are serious.