摘要
为探索长江河口生境条件改变对重要生物的影响状况,揭示生境条件对生物资源影响的机理,根据2010年5–6月在长江口进行的渔业资源与生态环境调查数据与历史资料,用根据扫海面积计算的栖息密度研究了鱼类群落结构的变动状况,以及5–6月鱼类群落结构及其与环境因子的关系。结果显示,2010年5–6月共记录鱼类40种。种类数目较多的科分别是鳀科和虾虎鱼科(均为5种),其次为石首鱼科(4种)及舌鳎科(3种);鱼类栖息密度以当年卵化幼鱼为主,矛尾虾虎鱼、棘头梅童鱼、凤鲚和刀鲚为栖息密度最大的4种鱼类,占调查区域鱼类栖息密度的94.11%。聚类分析和非度量多维测度分析发现,春季鱼类有明显的空间分布差异,除趋势典范对应分析的9个环境因子中,水深、表层盐度和底层盐度对河口内部鱼类丰度和栖息密度影响最大,而底层pH值、表层盐度和底层温度则对河口外部鱼类群落影响最大。与历史资料相比,目前记录的鱼类物种数目(40种)少于1985年5月或6月(69种,62种),而栖息密度(5.20×104ind/km2)高于1985年5月或6月(1.72×104 ind/km2,2.29×104 ind/km2)。本研究表明虽然长江口仍为棘头梅童鱼、刀鲚、凤鲚等重要经济鱼类的产卵场和肥育场,但是鱼类群落结构已经发生了较大的变化。
For studing the effect and mechanism of variability of habitat factors on important biological resources in the Yangtze River estuary（YRE）,we evaluated the relationship between fish community structure and envi-ronmental factors in the YRE.We collected fish by bottom trawling and obtained environmental data from 30 sta-tions in the YRE in May and June 2010.In addition,we used historical data to analyze the effect of large hydraulic projects on fish community dynamics in the YRE.We collected a total of 40 fish species belonging to 23 families and 12 formers.The Engraulidae and Gobiidae families were the most abundant（5 species each）,followed by Sciaenidae（4 species）,and Cynoglossidae（3 species）.The trawl catches were dominated by young-of-year juve-niles.The most abundant species（94.11% of the total catch） by life history type were Chaeturichthys stigmatias（resident）,Collichthys lucidus（marine migrant）,Collia mystus（semi-anadromous）,and Collia nasus（anadro-mous）.Cluster and non-metric multidimension scaling analysis revealed significant spatial variation in the fish community.Of the nine environmental variables we measured,water depth,bottom salinity,and surface salinity were the most significant factors influencing fish species richness and density in the inner zone.Conversely,the fish community in the outer zone was primarily influenced by the bottom pH,surface salinity,and bottom tem-perature.The number of fish species declined compared to historical catches in May（69 species,1.72×10^4ind/km2）and June（62 species,2.29×10^4ind/km2） in 1985,though fish density（5.2×10^4ind/km2） increased.Our results indicate the YRE has still been the spawming and nursery ground for commercial species,but fish commu-nity structure has varied.
出处
《中国水产科学》
CAS
CSCD
北大核心
2011年第5期1141-1151,共11页
Journal of Fishery Sciences of China
基金
国家重点基础研究发展计划项目(2010CB429005)
上海海洋大学研究生科研基金(A-2501-10-011405)
关键词
长江口
鱼类群落结构
栖息密度
环境因子
多元分析
the Yangtze River estuary
fish community structure
fish density
environmental factors
multivariate analysis
