Fish assemblage structure in the hypoxic zone in the Changjiang (Yangtze River) estuary and its adjacent waters  

作　　者：单秀娟 金显仕 袁伟 

机构地区：[1]Key Laboratory for Sustainable Utilization of Marine Fisheries Resource, Ministry of Agriculture, Key Laboratory for Fishery Resources and Eco-environment, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2010年第3期459-469,共11页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China (No. 30490233, 40906086);the National Basic Research Program of China (973 Program) (No. 2006CB400608);Taishan Scholar Program of Shandong Province, Postdoctoral creative foundation of Shandong Province and the Yellow & Bohai Sea Scientific Observation and Experiment Station for Fishery Resources and Environment, Ministry of Agriculture

摘　　要：Fish assemblage structure in the hypoxic zone in the Changjiang (Yangtze River) estuary and its adjacent waters were analyzed based on data from bottom trawl surveys conducted on the R/V Beidou in June, August and October 2006. Four fish assemblages were identified in each survey using two-way indicator species analysis (TWIA). High fish biomass was found in the northern part, central part and coastal waters of the survey area; in contrast, high fish diversity was found in the southern part of the survey area and the Changjiang estuary outer waters. Therefore, it is difficult to maintain high fishery production when high fish diversity is evenly distributed in the fish community. Fish became smaller and fish size spectra tended to be narrower because of fish species variations and differences in growth characteristics. Fish diversity increased, the age to maturity was reduced and some migrant species were not collected in the surveys. Fish with low economic value, small size, simple age structure and low tropic level were predominant in fish assemblages in the Changjiang estuary and its adjacent waters. The lowest hypoxic value decreased in the Changjiang estuary and its adjacent waters.Fish assemblage structure in the hypoxic zone in the Changjiang （Yangtze River） estuary and its adjacent waters were analyzed based on data from bottom trawl surveys conducted on the R/V Beidou in June, August and October 2006. Four fish assemblages were identified in each survey using two-way indicator species analysis （TWIA）. High fish biomass was found in the northern part, central part and coastal waters of the survey area; in contrast, high fish diversity was found in the southern part of the survey area and the Changjiang estuary outer waters. Therefore, it is difficult to maintain high fishery production when high fish diversity is evenly distributed in the fish community. Fish became smaller and fish size spectra tended to be narrower because of fish species variations and differences in growth characteristics. Fish diversity increased, the age to maturity was reduced and some migrant species were not collected in the surveys. Fish with low economic value, small size, simple age structure and low tropic level were predominant in fish assemblages in the Changjiang estuary and its adjacent waters. The lowest hypoxic value decreased in the Changjiang estuary and its adjacent waters.

关 键 词：the Changjiang estuary fish assemblage structure diversity size spectrum 

分 类 号：S917.4[农业科学—水产科学]