Selectivity of different alternative Cod ends and radial square mesh escape panels (RSEP)

Abstract

Bottom trawl fishery is carried out intensively throughout the season in the Black sea. For this reason, the selectivity effects of five codend with different mesh size, shapes and escape panels (commercial (40D), 50 mm diamond-shaped (50D), and 40 mm square-mesh (40S) and radial square mesh escape panels (RSEP) which were added to the front and back section of 40D) were investigated. Using a commercial fishing trawl, 44 valid hauls were carried out from August 23rd to October 24th 2016 on the Sakarya coast to the South west of the Black Sea. the L-50 value of commercial cod end was calculated as was 12.9 cm for Mullus barbatus (red mullet), and was improved in cod ends with RSEPs. Further, the L-50 values obtained from the other cod ends were found to be very high (40S: 15.62 cm, 50D: 15.24 cm). It was noticed that none of the cod ends showed sufficient selectivity for bluefish (Pomatomus saltatrix), which was caught as bycatch. the comparative account of the findings of current study with the previous studies advocates that the cod ends need to be made from PA netting and RSEP should be applied for more escape area.