A comparison between benthic gillnet and bottom trawl for assessing fish assemblages in a shallow eutrophic lake near the Changjiang River estuary  

作　　者：LI Yalei LIU Qigen CHEN Liping ZHAO Lianjie WU Hao CHEN Liqiao HUT Zhongjun 李亚雷;刘其根;陈丽平;赵良杰;吴昊;陈立侨;胡忠军(Key laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China;Xinyang College of Agriculture and Forestry, Xinyang 464000, China;Nanjing Institute of Environmental Science, Ministry of Environmental Protection, Nanjing 210042, China;School of Life Science, East China Normal University, Shanghai 200062, China)

机构地区：[1]Key laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai 201306, China [2]Xinyang College of Agriculture and Forestry, Xinyang 464000, China [3]Nanjing Institute of Environmental Science, Ministry of Environmental Protection, Nanjing 210042, China [4]School of Life Science, East China Normal University, Shanghai 200062, China

出　　处：《Journal of Oceanology and Limnology》2018年第2期572-586,共15页海洋湖沼学报（英文）

基　　金：Supported by the Science and Technology Commission of Shanghai Municipality(Nos.08DZ1203101,08DZ1203102);the Shanghai University Knowledge Service Platform,Shanghai Ocean University Aquatic Animal Breeding Center(No.ZF1206)

摘　　要：Two fishing methods including gillnetting and trawling to estimate attributes of fish assemblage were compared in Dianshan Lake from August 2009 to July 2010. Species composition dif fered significantly between the gears, with four significant contributors in gillnet catches and one in trawl catches. Trawling collected more proportions of benthic species by number and biomass than gillnetting. Size distribution was significantly influenced by fishing technique; gillnetting captured relatively less small-sized fishes and trawling captured less large-sized individuals. Trawling produced species richness closer to the one expected than gillnetting. On the whole, trawl catch was a quadratic polynomial function of gillnet catch and a significantly negative correlation was found between them, both of which varied as dif ferent polynomial functions of temperature. However, trawl and gillnet catches were significantly correlated only in one of five month groups. It is concluded that single-gear-based surveys can be misleading in assessments of attributes of fish assemblages, bottom trawling is a more ef fective gear for assessing fish diversity than benthic gillnetting, and using gillnet catches as an indicator of fish density depends on fishing season in the lake.Two fishing methods including gillnetting and trawling to estimate attributes offish assemblage were compared in Dianshan Lake from August 2009 to July 2010. Species composition differed significantly between the gears, with four significant contributors in gillnet catches and one in trawl catches. Trawling collected more proportions of benthic species by number and biomass than gillnetting. Size distribution was significantly influenced by fishing technique; gillnetting captured relatively less small-sized fishes and trawling captured less large-sized individuals. Trawling produced species richness closer to the one expected than gillnetting. On the whole, trawl catch was a quadratic polynomial function of gillnet catch and a significantly negative correlation was found between them, both of which varied as different polynomial functions of temperature. However, trawl and gillnet catches were significantly correlated only in one of five month groups. It is concluded that single-gear-based surveys can be misleading in assessments of attributes of fish assemblages, bottom trawling is a more effective gear for assessing fish diversity than benthic gillnetting, and using gillnet catches as an indicator offish density depends on fishing season in the lake.

关 键 词：fishing gear expected species richness size structure catch per unit effort temperature 

分 类 号：P[天文地球]