龙开口水电站坝上坝下鱼类群落结构变化趋势

Variation Trend of Fish Community in Upper and Under Longkaikou Dam

2016年3月至2017年4月在龙开口水电站库区和坝下江段开展鱼类资源调查,库区6个采样点,坝下3个采样点,共采集到鱼类4目9科32属42种。坝上坝下鱼类主要类群较为一致,但是坝下鱼类资源更为丰富,其鱼类群落多样性指数2.751和丰富度指数5.322均高于坝上。但是与建坝前相比,库区鱼类群落结构由流水型鱼类向水库型演变,坝下鱼类总种类锐减12种。总之,同建坝前相比,龙开口坝上坝下处于鱼类群落演变期,其中坝下资源呈萎缩状态,本次调查中坝下江段尚未采集到的四川裂腹鱼、中华金沙鳅、前臀鮡、安氏高原鳅等具有保护价值的特有鱼类。

Fish resources investigation was carried out in the reservoir area of Longkaikou Hydropower Station and the lower reaches of the dam from March 2016 to April 2017.Four orders,9 families,32 genera and 42 species of fish were collected in six sampling points and three sampling points under the dam.The main fish species under the dam are consistent,but the fish resources under the dam are more abundant.The diversity index of fish community 2.751 and richness index 5.322 are higher than those above the dam.However,compared with before dam construction,the fish community structure in the reservoir area has evolved from flowing fish to reservoir type,and the total species of fish under the dam have dropped sharply by 12 species.In a word,compared with the period before dam construction,the upper and lower reaches of Longkaikou Dam are in the evolution period of fish communities,in which the resources under the dam are shrinking.The endemic fishes to upper reaches of Yangtze river like Schizothorax kozlovi,Jinshaia sinensis,Pareuchiloglanis anteanalis,Triplophysa angeli which valued for protection had not been collected.