Considerable by-catch problems have occurred in the commercial beam trawl
fishery targeted at deep water pink shrimp in the Sea of Marmara. In this study, the grid
systems were used to reduce the untargeted catch and improve the species' selectivity.
By-catch reduction ratios of the beam trawls deployed with and without the grid were
compared by the parallel hauling method. Selectivity values of 20 mm bar spacing grid
and 24 mm mesh size cod-end were also analyzed by SELNET program. In general, bycatch reduction ratios of the grid beam trawl were determined as 50.6% and 56.9% in
terms of number and weight, respectively. The reduction of target catch (Parapenaus
longirostris) in the same gear was found to 23.1% in terms of number and 23.2% in
terms of weight. In the model for rose shrimp, obtained according to the lowest AIC
value, the selectivity parameters of the grid for L50 were 13.51 cm and for SR 4.76 cm.
Selectivity parameters of the same species for 24 mm mesh size cod-end were; L50 = 8.99
cm and SR = 5.56 cm. These results indicated that grid usage benefits and contribute to
sustainable fishery in the target catch-oriented fishing applications.