A study on the catch composition, by catch in the shrimp beam trawl

A STUDY ON THE CATCH COMPOSITION AND BYCATCH IN THESHRIMP BEAM TRAWLABSTRACTCatch production, catch composition, bycatch, and discard of shrimp beam trawlwere studied in Marmara Sea.A total of 36 species belonging to 4 groups were captured by beam trawl duringthe survey. The catch biomass comprised 51,3 % arthropoda, 30,9 % fish, 15,5 %echinodermata and 1,3 % mollusca. The deep water pink shrimp (Parapenaeuslongirostris) formed 50,8 % of the total biomass catch.Catch production in beam trawl fishery was calculated as 10,1 kg/h. On average0,42 kg discard, 0,62 kg bycatch, and 1,04 kg non-target species per 1 kg shrimp werecaptured by the beam trawl.The sex ratio, length-weight relationship and size frequency distribution of deepwater pink shrimp were studied for each sex using 1942 specimens. Females made up55 % of the individuals. The total length ranged from 47 mm to 154 mm and weightfrom 1,5 g to 19,1 g in females the total length ranged from 58 mm to 120 mm, andweight from 1,41 g to 10,6 g in males. The length-weight relationships estimated forfemales and males were W=0,0057*L2,95 (r=0,97) and W=0,0112*L2,59 (r=0,93),respectively.Keywords: Parapenaeus longirostris, beam trawl, discard, bycatch, catch composition,Marmara seaII