Comparative Analysis of Various Trawl Codend Selectivity forRed Mullet (Mullus barbatus) and Whiting (Merlangiusmerlangus) in the Black Sea
Makaleler > Tam Makale · 2025
Yazarlar: Hamdi Moussa, Mehmet Cilbiz, Uğur Uzer, Celalettin AYDIN, Taner Yıldız, İbrahim Tamer Emecan, Firdes Saadet Karakulak
TURKISH JOURNAL OF FISHERIES AND AQUATIC SCIENCES, SCI İndekslerine Giren Dergi, Uluslararası, Wos, 2025, cilt 26, ss 1-10
DOI: 10.4194/TRJFAS28144
Özet
<p>The aim of this study was to estimate the selectivity of 40 mm (40D) and 44 mm (44D)diamond mesh size, 40 mm square (40S), and turned (40T) mesh codend for red mullet(Mullus barbatus) and whiting (Merlangius merlangus). Samples were collected fromtwo locations in the western Black Sea during 21-28 July 2020 using covered codendmethod was used in experiment. For red mullet, the mean fifty-percent retentionlength (L50) values for 40D, 40S, 40T and 44D were estimated at 8.55 (8.02–8.93) cm,12.04 (11.03–12.80) cm, 11.46 (10.11–11.99) and 13.23 (12.69–13.71) cm respectively.L50 values of 40D, 40S, 40T and 44D were determined as 10.06 (8.59–12.58) cm, 15.61(14.74–16.24) cm, 15.45 (14.48–15.54) cm, 13.56 (12.63–14.11) cm for whiting,respectively. The estimated L50 of the commercially used 40D codend was lower thanthe Minimum Conservation Reference Size (MCRS) for red mullet and whiting (13 cm).All tested experimental codends improved the size selectivity of the studied speciescompared with the legally allowed minimum mesh size (40 mm). In addition, thediscard rate for red mullet using the 40D codend, which is commonly employed in theBlack Sea, was found to be 97.90%. The implementation of 40S codends could reducethis rate to approximately 84.57%. Similarly, for whiting, the discard rate decreasedfrom approximately 74.09% to 59.03%, depending on the tested experimentalcodends. The size selectivity and exploitation pattern of codends for red mullet andwhiting could be improved by simply changing to square (40S) or turning (40T) meshes,based on MCRS. Also, the present study provides the scientific foundation for theregulation concerning the increase of the codend mesh size of diamond 44 mm in trawlfishing in the Black Sea, which is scheduled for implementation in 2028.</p>