广东韩江潮州江段鱼类多样性及季节变化

Fish species diversity and its seasonal variations in the Chaozhou section of Hanjiang River, Guangdong Province

为了解韩江潮州江段鱼类生物多样性及季节变化,2012年5月至2013年4月,采用定置刺网和地笼网对韩江潮州江段5个样点开展了渔获物调查。共采集鱼类53种,隶属8目19科48属,以鲤形目和鲈形目为主,分别为27种和11种,占总种数的50.9%和20.8%;其中13种为该水域新记录种;广东鲂(Megalobrama terminalis)、福建小鳔鮈(Microphysogobio fukiensis)、赤眼鳟(Squaliobarbus curriculus)和鲮(Cirrhinus molitorella)为全年优势种。Shannon-Wiener多样性指数(H')、Pielou均匀度指数(E)和Margalef种类丰富度指数(D)均表现出夏季最高,其后依次是秋季、冬季、春季;Simpson指数(D')秋季最高,其后是夏季、冬季、春季;Bray-Curtis尾数/种类相似性系数聚类分析和非度量多维标度分析在38.23%的水平上将12个月分为2个群聚:I包括夏、秋季节6个月,II包括春、冬季节6个月,这与多样性指数H'、E、D和D'的变化趋势一致,表明韩江潮州江段鱼类资源的季节变化显著,水温和流量是影响该江段鱼类资源的主要环境因子。10个主要物种被聚合为两大类群,分别为季节性出现的小型鱼类和常见种。我们认为保护栖息环境、建立适宜的禁渔制度是保护该江段鱼类资源的关键措施。

To understand the status of fish species diversity and seasonal variation in the Chaozhou section of Hanjiang River, a survey was carried out at five sample sites using fixed gillnets and cage nets from May 2012 to April 2013. In this study, 53 fish species, belonging to 8 orders, 19 families and 48 genera, were collected. Results indicated that Cypriniformes and Perciformes were the dominant groups with 27 and 11 spe- cies and accounting for 50.9% and 20.8% of the total species, respectively. Compared with earlier research, there were 13 new species recorded. The dominant species were Megalobrama terminalis, Microphysogobio fukiensis, Squaliobarbus curriculus and Cirrhinus molitorella, which accounted for 65.78% of the total sam- pies. Shannon-Wiener index （H＇）, Pielou＇s evenness index （E＇） and Margalef richness index （D） were the highest in summer, followed by those in autumn, winter, and spring; Simpson index （D） was the highest in autumn, followed by those in summer, winter, and spring. A cluster analysis and non-metric mul-ti-dimensional scaling ordination of Bray-Curtis similarity data based on species and abundance showed that the 12 months could be divided into 2 groups at a 38.23% similarity level, i.e. group I comprised six months of summer and autumn, while group II comprised six months of spring and winter, which is consistent with the variations in the diversity indices H＇, E, D and D＇. These results indicated significant seasonal variations in fish resources among seasons. Water temperature and flow were suggested as the key drivers on fish re- sources in this area. Based on their appearance, 10 major fish species can be divided into two groups; Group A was characterized by small fish that appeared seasonally, while group B contained common species. In addition, it proposes that the habitat protection and the establishment of appropriate fishing regulations are the key measures to protect fish stocks in the Chaozhou section of Hanjiang River.