摘要
We conducted acoustical surveys with a horizontal beam transducer to detect fish and with a vertical beam transducer to detect depth and macrophytes in two typical shallow lakes along the middle and lower reaches of the Changjiang(Yangtze) River in November 2013. Both lakes are subject to active fish management with annual stocking and removal of large fish. The purpose of the study was to compare hydroacoustic horizontal beam estimates with fish landings. The preliminary results show that the fish distribution patterns dif fered in the two lakes and were af fected by water depth and macrophyte coverage. The hydroacoustically estimated fish biomass matched the commercial catch very well in Niushan Lake, but it was two times higher in Kuilei Lake. However, acoustic estimates included all fish, whereas the catch included only fish >45 cm(smaller ones were released). We were unable to determine the proper regression between acoustic target strength and fish length for the dominant fish species in the two lakes.
We conducted acoustical surveys with a horizontal beam transducer to detect fish and with a vertical beam transducer to detect depth and macrophytes in two typical shallow lakes along the middle and lower reaches of the Changjiang （Yangtze） River in November 2013. Both lakes are subject to active fish management with annual stocking and removal of large fish. The purpose of the study was to compare hydroacoustic horizontal beam estimates with fish landings. The preliminary results show that the fish distribution patterns differed in the two lakes and were affected by water depth and macrophyte coverage. The hydroacoustically estimated fish biomass matched the commercial catch very well in Niushan Lake, but it was two times higher in Kuilei Lake. However, acoustic estimates included all fish, whereas the catch included only fish 〉45 cm （smaller ones were released）. We were unable to determine the proper regression between acoustic target strength and fish length for the dominant fish species in the two lakes.
作者
LIAN Yuxi
HUANG Geng
Matgorzata GODLEWSKA
CAI Xingwei
LI Chang
YE Shaowen
LIU Jiashou
LI Zhongjie
连玉喜;黄耿;Ma?gorzata GODLEWSKA;蔡杏伟;李昌;叶少文;刘家寿;李钟杰(State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences;Research Center of Aquatic Organism Conservation and Water Ecosystem Restoration in Anhui Province, Anqing Normal University;University of Chinese Academy of Sciences;Polish Academy of Sciences, European Regional Centre for Ecohydrology)
基金
Supported by the Special Scientific Research Fund of Agriculture Public Welfare Profession of China(No.201303056)
the State Key Laboratory of Freshwater Ecology and Biotechnology(No.2011FBZ28)
the Science and Technology Research Project of China Three Gorges Corporation(No.CT-12-08-01)
