连江鱼类群落多样性及其与环境因子的关系

目前连江梯级开发至12级,为了解梯级开发后连江鱼类群落状况,于2009年3月和2010年4月对连江上、中、下游7个代表江段的鱼类群落结构以及环境因子分别进行了调查,共采集鱼类98种,分属于9目20科75属。海南墨头鱼Garra pingi hainanensis、南方长须鳅鮀Gobiobtia longibarba meridionalis为连江新纪录种。银鮈Squalidus argentatus、黄颡鱼Pelteobagrus fulvidraco、小鳈Sarcocheilichthys parvus、马口鱼Opsariichthys bidens、餐Hemiculter lecuisculus等小型鱼类在鱼类群落结构中占优势地位。对鱼类群落进行聚类分析(CLUSTER)和非度量多维标度排序(NMDS)分析结果表明连江鱼类被划分为3个类群,即下游河口类群、中下游类群及中上游类群;S2、S3两个站位鱼类物种多样性(H’)、丰富度(D’)和均匀度(J’)均高于其他站位。通过对连江各站位鱼类群落与环境因子的典型对应分析发现:河宽、温度、海拔、pH值和水坝之间的距离5个因子与鱼类群落相关性较强(P<0.05)。与历史资料对比后发现,连江鱼类种类、分布、生态类型都发生了巨大变化。

Relationship between fish community diversity and environmental factors in the Lianjiang River, Guangdong, China

Up to now, 12 dams have been built along Lianjiang River for about 50 years. Parted fluvial water area had been relative aquicolous ecosystem. In order to study the effect of these dams to fish, Fish community had been investigated at seven reach of Lianjiang River from 2009 to 2010. 98 species were collected belonging to 9 orders, 20 families and 75 genura. Garra pingi hainanensis and Gobiobtia longgibarba meridionalis was newly recorded in Lianjiang River. The top five species in sequence were Squalidus argentatus, Sarcocheilichthys parvus , Pelteobagrus fulvidraco, Pelteobagrus fulvidraco, Opsariichthys bidens and Acrossocheilus parallens. The spatial pattern of fish community was analyzed using higerarchical and non-metric multidimensional scaling. The fish community of Lianjiang River can be distinguished three cluster middle-upriver cluster, middle-downriver reach cluster and downriver cluster. The Shannon-Weiner index, Pielou evenness index and species richness index of Station S2 and S3 is higher than other station. Canonical correspondence analysis showed that the width, Water temperature, Height , PH and the distance between two dams is the significant factors correlation with the fish community. Compared with historic data, the distribution , species and the fish ecology type changed greatly.