中文摘要：

为摸清乌江下游干流现有的鱼类种类组成和物种多样性状况,探索水电开发对鱼类群落多样性的影响,本研究于银盘电站蓄水前的2006–2008年和蓄水后的2011–2013年,采用渔获物调查方法对乌江下游沿河至白马干流江段鱼类进行了调查。两次调查共采集鱼类105种,其中2006–2008年采集到100种,2011–2013年采集到62种;两次调查相比,广适性鱼类减少10.38%,湖沼定居型鱼类减少0.98%,喜流水性鱼类减少9.62%。两个时期的鱼类群落多样性分析显示：各个调查江段Margalef丰富度指数（R）和Shannon-Wiener多样性指数（H）在2011–2013年均低于2006–2008年。渔获物分析结果表明：大鳍鳠（Mystus macropterus）、中华倒刺鲃（Spinibarbus sinensis）、瓣结鱼（Tor（Folifer）brevifilis）等鱼类在渔获物中的重量比例从2006–2008年间的大于5%,下降到2011–2013年间的不足2%,而（Hemiculter leucisculus）、草鱼（Ctenopharyngodon idellus）、黄颡鱼（Pelteobagrus fulvidraco）等在2011–2013年渔获物中的重量比例有所上升,成为调查区域的主要渔获对象。丰度生物量比较表明：2006–2008年鱼类群落结构受到中等程度的干扰,而2011–2013年受到严重程度的干扰。为保护乌江下游的鱼类生物多样性,需采取现有栖息地修复、控制过度捕捞等多种资源保护方式。

英文摘要：

To understand the status of fish species diversity in the lower reaches of Wu River and to assess the impacts of hydropower station development on fish species diversity, two surveys were carried out along the Yanhe to Baima section in the mainstream of the lower reaches of Wu River from 2006 to 2008（the time period before the sluice of Yinpan and Pengshui hydropower station） and from 2011 to 2013（the time period after the sluice of Yinpan and Pengshui hydropower station） respectively by using fishery catch surveys. One hundred and five fish species were found from the two surveys, of which 100 fish species were sampled during 2006 and 2008, while only 62 fish species were found during 2011 and 2013. When the two datasets were compared, we found that the number proportion of eurytopic fish species, limnophilic fish species and rheophilic fish species in the catches of 2011–2013 decreased by 10.38%, 0.98% and 9.62%, respectively. Species diversity analysis indicated that the values of Margalef richness index（R） and Shannon-Wiener diversity index（H） during 2011 and 2013 were lower than those found during 2006 and 2008. Fishery catch structures indicated that the weight proportions of some species, such as Mystus macropterus, Spinibarbus sinensis, and Tor（Folifer） brevifilis, decreased from over 5% in the fishery catches of 2006–2008 to less than 2% in 2011–2013, but that the weight proportions of other species, such as Hemiculter leucisculus, Ctenopharyngodon idellus, and Pelteobagrus fulvidraco, had the greatest increase in the catches of 2011–2013 when compared with that of 2006–2008. Abundance biomass comparison showed that fish community structure of the mainstream of the lower reaches of the Wu River showed a moderately disturbed pattern during 2006 and 2008, but a seriously disturbed pattern during 2011 and 2013. To protect fish biodiversity of the lower reaches of Wu River, multiple protection measures, including habitat restoration and controls on overfishing must be applied by