Gökçeada Civarı (Kuzey Ege Denizi) Trol Balıkçılığının Ekonomik Balık Stoklarına Etkisi ve Baskın Türün Popülasyon Dinamiği

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Thesis Type: Doctorate

Institution Of The Thesis: Istanbul University, Faculty of Aquatic Sciences, Department of Marine and Freshwater Resources Management, Turkey

Approval Date: 2017

Thesis Language: Turkish

Student: Uğur UZER

Supervisor: Bayram Öztürk

Open Archive Collection: AVESIS Open Access Collection

Abstract:

In this study, the total and discard catch obtained from the Gokceada Island (northern Aegean Sea), one of the important fishery region of the Aegean Sea, were assessed in depth contours of 50-200 m and 200-400 m and population parameters of the European hake which is target species, was calculated. During the study, a total of 74 bony fishes, 12 cartilaginous fishes, 13 crustaceans, 12 mollusks and 12 echinoderms were identified. The total discard ratio was calculated as 25.9% and it has been found to reduce the discard rate with increasing depth. The mean CPUE was 16.83±7.49 kg/hour for three fishing seasons. While DPUE values were ranged between 1.40 and 19.77 kg/hour, an average DPUE was calculated as 4.47 ± 2.89 kg/hour. Total length distribution of European hake population ranged between 5.9 cm and 51.2 cm. The von Bertalanffy growth parameters were calculated as L∞=102,66 cm, W∞=10424 g, k=0,0992 and t0= -0,8085. It was found that there is an excessive fishing pressure and growth overfishing on the European hake stocks which are the target species.