海河流域大清河水系的鱼类多样性

大清河水系是海河流域最重要的组成部分，了解其鱼类多样性现状及特征对于京津冀一体化背景下流域水生生态保护有重要的科学价值。2018-2019年对大清河水系鱼类进行多次调查，并结合历史文献资料对大清河鱼类进行了详细梳理；以α多样性分析方法为基础，通过不同多样性指数反映大清河鱼类多样性现状。结果显示，大清河水系统计鱼类共85种，其中自然分布的淡水鱼类有8目、17科、59属、78种，以广布种为主，珍稀濒危物种占比低是大清河鱼类组成的重要特征；现状调查到鱼类42种，其中水系自然分布的种类仅33种，且以小型鱼类为主。Margalef丰富度指数、Shannon-Wiener多样性指数、Pielou均匀性指数分别为1.98、1.14、0.81，与海河流域其他水系相比，大清河水系鱼类物种多样性较低，且各区域分布较均匀。目前流域鱼类区系的完整性已被严重破坏，鱼类多样性呈现出明显的下降趋势。经济发展驱动的用水需求增加和大清河水资源不足是导致鱼类多样性减少的主要原因，生境变化、水域污染、水工建设、过度捕捞等也是不可忽视的因素。研究表明，保证一定生态流量、恢复河流连通性、加强水污染治理、开展人工增殖放流、加大禁...

Fish Community Diversity in the Daqing River System of Haihe River Basin

In order to understand the fish species composition of the Daqing River system, several field surveyswere conducted from 2018 to 2019. Based on field surveys data and relevant literatures, the results showed that there were 85 fish found in the Daqing River basin including 78 freshwater species, which belongs to 59 genera, 17 families and 8 orders. High proportion of common fish, low proportion of threatened and endemic species are characters of fish diversity of the Daqing River system, which could well-represent the fish fauna of the Haihe River. However, we only could collected 42 species during surveys. Only 33 of them are naturally distributed in the river. The average value Margalef richness index, Shannon-Wiener diversity index and Pielou evenness index of fish in Daqing River system were 1.98, 1.14 and 0.81 respectively, indicating that the species diversity of the Daqing River system was general and the distribution of each region was relatively uniform. Overall, the integrity of fish fauna has been destroyed. The species diversity is dramatically decreasing. The conflicts between the water demands from economic development and limited water resources are a primary infector causing the collapse of fish species diversity. Additionally, habitat degradation, water pollution, dam construction, and over-exploitation are all factors which should not be ignored. Maintaining a certain ecological discharge, restoring river connectivity, enhancing pollution management, applying the stock enhancement, and forbidding fish capture are effective means to improve the fish diversity.