Selectivity of 40 mm Square and 90º turned mesh codend for the Eurpean hake Merluccius merluccius and Blue whiting (Micromesistius poutassou).

Abstract

Marine and Life SciencesIn this study, it was investigated that to determine the selectivity of 40 mm square (40S) and 90º turned mesh (40T90) codend for the european hake (Merluccius merluccius) and blue whiting (Micromesistius poutassou). Fishing experiments were conducted on the international waters of the Aegean Sea by using 1200 mesh tailored trawl. Codends have knotted polyethylene (PE) 380d/21 no rope thickness and 5 m in lengths. The hooped covered codend technique was employed for the estimated codend selectivity. The selectivity parameters were estimated by using SELNET software. The plots were made with R (v.4.0.3) based RStudio (v.1.4.1106) software using the "ggplot2 (v.3.3.3)" package. Nineteen successful hauls, 11 with 40S and 8 with 40T90 codends, were performed. The mean L 50 values (50% retention length) of 40S and 40T90 were found to be a 13.23 cm and 12.55 cm total lengths for the european hake and 23.73 cm and 19.91 cm total lengths for the blue whiting, respectively.