Revealing the Fluttering Motions of Mid-Water Trawl Codend Through Sea Trials:Case Study of Antarctic Krill Trawl Codend  

作　　者：LIU Wei TANG Hao NYATCHOUBA NSANGUE Bruno Thierry ZHANG Feng YIN Liqiang XU Liuxiong HU Fuxiang LIU Pengfei 

机构地区：[1]College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,China [2]National Engineering Research Center for Oceanic Fisheries,Shanghai 201306,China [3]Key Laboratory of Oceanic Fisheries Exploration,Ministry of Agriculture and Rural Affairs,Shanghai 201306,China [4]The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources,Shanghai Ocean University,Ministry of Education,Shanghai 201306,China [5]Scientific Observing and Experimental Station of Oceanic Fishery Resources,Ministry of Agriculture and Rural Affairs,Shanghai 201306,China [6]Faculty of Marine Science,Tokyo University of Marine Science and Technology,Minato,Tokyo 108-8477,Japan [7]Tendering Office,Shanghai Ocean University,Shanghai 201306,China

出　　处：《Journal of Ocean University of China》2023年第2期555-564,共10页中国海洋大学学报（英文版）

基　　金：This study was supported by the National Natural Science Foundation of China(No.31902426);the Shanghai Sailing Program(No.19YF1419800);the Special Project for Exploitation and Utilization of Antarctic Biological Resources of the Ministry of Agriculture and Rural Affairs(No.D-8002-18-0097).

摘　　要：The dynamic coupling between the fluttering motions and hydrodynamic characteristics of codend is essential in understanding the trawl selectivity through fish response and the drag force acting on the whole trawl.This study investigated the effect of towing speed,warp length,warp tension,and catch size on the fluttering motions of Antarctic krill trawl codend during net shooting,towing,and hauling by using sea trial data.The time-periodicity of codend oscillation was analyzed by the Morlet wavelet transform method.Results indicated that the period of codend oscillation was between 50 s and 90 s and showed an increasing trend with the warp tension but a decreased value at the towing stage.The coefficient amplitude of codend oscillation was between 0 and 4 at the net shooting and hauling stages,and between 0.2 and 0.6 at the towing stage.The amplitude of codend oscillation increased with the warp tension,towing speed,and catch size,but decreased with the increase of the warp length.In addition,the period of codend oscillation increased with the towing speed at the net shooting and hauling stages,but decreased at the towing stage.These results from codend fluttering motions can improve the understanding of fish behavior and gear shape that modify the hydrodynamic force on the codend instantaneously.

关 键 词：codend fluttering motions sea trials Morlet wavelet PERIODICITY 

分 类 号：S972.13[农业科学—捕捞与储运]