九段沙湿地潮沟鱼类组成的时空格局

九段沙湿地是典型的长江口沙洲,对长江和东海鱼类资源有重要的影响。为了解九段沙湿地鱼类多样性及变化趋势,于2009至2012年对其进行了16次调查,结果显示:(1)4年在九段沙湿地捕获鱼类12 477尾,共96种,新记录鱼类15种;(2)结合历史资料,至2012年底九段沙湿地共记录鱼类158种,以鲈形目种类居多,有54种;鲤形目次之,共27种;(3)优势种有斑尾刺虾虎鱼(Acanthogobius hasta)、(Liza haematocheila)、棱(Liza carinatus)、刀鲚(Coilia ectenes)、凤鲚(Coilia mystus)和中国花鲈(Lateolabrax maculates);(4)上沙、中沙和下沙鱼类组成存在差异,盐度是影响鱼类组成结构的重要因素。研究表明九段沙湿地鱼类资源较丰富,具有长江口鱼类区系特征,但鱼类多样性呈逐年降低的趋势,种类组成也逐年在发生变化。

Temporal and spatial distribution patterns of fish species composition in intertidal creek of Jiuduansha wetland

Jiuduansha Wetland is a typical shoal in Yangtze River estuary, which has ichthyic fauna characteristics of Yangtze River estuary. In order to comprehend the composition of fish community, community diversity and its variation trend, 16 surveys from 2009 to 2012 were made, the result showed that: (1)A total number of 12477 individuals were collected belonging 103species. (2)Among all the species, the Order Perciformes was at a dominant position, whose species were 55, the family cypriniformes ranked only second to the order Perciformes, comprising 28 species. (3)The dominant species were Acanthogobius hasta, Liza haematocheila, Liza carinatus, Coilia ectenes, Coilia mystus and Lateolabrax maculates. (4) Jiudunansha wetland was made up of species from 6 different ecological groups: fresh water fish, resident species, seasonally entering estuary wetland species, anadromous species, catadromous species, and occasionally entering estuary wetland species. (5) On the basis of diversity analysis, the catches and diversity of fish community decreased year by year. (6)The the similarity analysis of waters with different similarity in Jiuduansha wetland revealed that significant difference appeared among Shangsha, Zhongsha and Xiasha.The fishery resources of Jiuduansha wetland was abundant ,but it has reduced in recent years, and the possible reasons that caused the reduce of its diversity are overfishing, water pollution, loss of habitat, and so on.