Catch composition and efficiency of swordfish longline fishery in the Gulf of Antalya

Swordfish (Xiphias gladius Linnaeus, 1758) has been produced in high-level fishing activities. There are many studies on swordfish in the world. Nevertheless, it has been thought that there is a lack of work on this fish around Gulf of Antalya. This research has been carried out in order to provide a better source of information about the Swordfish. In this study, a total of 122 fishing operations were carried out between 9 December 2015 to 3 February 2017, 12 miles off the Antalya Gulf. A total of 221 Swordfish has been caught. Seven fish species belonging to 6 families, including Gempylidae, Lamnidae, Scombridae, Dasyatidae, Istiophoridae and Coryphaenidae were caught as bycatch. The mean CPUEs for swordfish by number (CPUEN) and weight (CPUEB) were computed as 5,99±0,43 specimens 134,23±11,53 kg per 1000 hooks. Lenght-weight relation of caught swordfish were calculated as W = 0,0000005 LJFL3,65 , R² = 0,967 and positive allometry found out as result. In addition, an expense of approximately 574 TL has been calculated for one swordfish fishing operation with longline. A large proportion of this expense (57%) was made up of bait. In the economic analysis of the income (943,95 TL) and outcome (574 TL), it is estimated that an operation yields is about 369 TL.