Investigation of selectivity characteristics of gill and trammel nets used in supplying bait to set line fishing in Yumurtalık Bay

Within the scope of this study, catch composition, by-catch rate and selectivity parameters of the gill and trammel nets used to supply bait to set line were determined. In order to obtain the data, 15 surrounding fishing operation were carried out in Yumurtalık Bay between 07.03.2020 and 20.07.2020, with gill and trammel net with 16mm and 18mm mesh size. In addition, the number of hooks set into the sea to catch bluefish and sea bass during a fishing season (fishing effort) and the amount of fish consumed as bait were determined. Face-to-face interviews were made with the fishermen. Obtained results showed that there was no difference in terms of species composition, by-catch rate and length distribution between 16mm gill and trammel nets. However, it was observed that the by-target catch rate, which was 41% in the 16mm trammel net, decreased to 22% in the 18mm trammel net. For Chelon auratus caught with trammel nets, the selectivity factor was determined to be 10.88 and optimum capture length of, 16mm and 18mm nets 17.40 cm and 19.57 cm, respectively. Interviews with fishermen; showed that in one season, 67680 hooks were set into the sea and approximately 3.2 tons of mullet was used as bait.