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Shrimp beam trawl fishery is one of the important coastal fisheries in Korea . It has a regulation to the length of beam (8 m) andwing net (7 m) of shrimp beam trawl that has been used in the district of Junlanam -do and Gyungsangnam -do . This regulationwas made in relation to the size of shrimp beam trawler of 3- ton class at that time . Now the shrimp beam fishing vessel has alimit not greater than 5 tons in gross ton . Recently , with improvement of fishing industry and fishing vessel fishermen asked theexpansion of the length of beam and wing net , therefore it is necessary to investigate the effect of lengthening the beam andwing net length . Three different beams (8 m, 10 mand 12 min length ) and three different wing net (7 m, 10 mand 13 min length )were made and the experiment was conducted near Narodo of Goheng by two fishing vessels of 4.98 and 4.88 tons in gross tonbetween June 2011 and October 2012. When the length of wing net was increased from 7m to 10 m and 13 m, the relative catchratio in total biomass was increased 25% and 79% for shrimp , (17% and 22% in total ), respectively . And when the beam lengthwas increased from 8mto 10 mand 12 m, the relative catch ratio was increased 35% and 84% for shrimp , (21% and 37% in total ),respectively . The force exerted to the iron guide of inhauler ’swith the beam length of 8mwas about 30% greater than that withthe beam length of 10 m when hauling the shrimp beam trawl net .Keywords : Beam length , Wing net length , Catch efficiency , Operation safety , Shrimp beam trawl |
