Effect of hook size catch efficiency on common carp (Cyprinus carpio): A case study in Turkish recreational fishery

The present study aimed to determine the catch efficiency of hooks of different sizes commonly used in recreational common carp fishing in Türkiye. The investigation was conducted over a period from April 2018 to April 2020 in Keban Dam Reservoir, encompassing a total of 38 fishing operations during which three different hook sizes (No. 4, No. 5, and No. 6) were evaluated. A total of 162 common carp specimens were captured, ranging from 26.1 to 86.4 cm in total length. While no statistically significant differences were detected in sample sizes among hook size categories, significant differences were observed in mean total fish length. 27 Increasing hook size resulted in proportionally increased mean catch length. The findings demonstrated that hook size significantly influences the length distribution of common carp captures. Notably, increasing hook size reduced the capture efficiency for undersized individuals (below MCRS) and consequently decreased the discard rate resulting from undersized catches. Utilization of hook No. 6 could reduce the discard rate from 44.90% to 14.04%. Based on these findings, it is recommended that the use of hooks No. 4 and smaller in recreational common carp angling in Türkiye be restricted.