Multifilament ve monofilament fanyalı uzatma ağları ile avlanan hedef dışı balıkların ağlar üzerindeki dağılımları
Bu araştırmada Karadeniz’in Sinop kıyılarında 1 Ocak 2002 ve 31 Aralık 2002 tarihleri arasında fanyalı uzatma ağları ile avlanan hedef dışı balık türlerinin ağlar üzerindeki dağılımları tespit edilmiştir. Çalışmada multifilament (Fml) ve monofilament (Fmn) materyale sahip, tor ağ göz açıklığı 36 mm, fanya göz açıklığı 200 mm olan uzatma ağları kullanılmıştır. Balıkların dikey yöndeki konum tespiti için yükseklikteki fanya göz sayısı (7 göz), dikkate alınmıştır. Yatay yöndeki konum için donatılmış ağın mantar yakası 10 eşit parçaya ayrılarak işaretleme yapılmıştır. Araştırmada toplam 286 adet hedef dışı balık (Scorpeana porcus, Gaidropsarus mediterraneus, Solea spp., Gobius spp. ve Labrus spp.) yakalanmıştır. Balıkların 188 adeti Fml ağ ile 98 adedi ise Fmn ağ ile avlanmıştır. Her iki ağda balıklar %76,1 ve %77,6’lık oranlarla en fazla alt kısımlarda (1 ve 2. Fanya) yakalanma dağılımı göstermiştir. Demersal özellik gösteren bu balıkların orta (3, 4 ve 5. Fanya) ve üst bölümlerde (6 ve 7. Fanya) daha az yakalandığı belirlenmiştir. Sonuçları, fanyalı uzatma ağlarında hedef dışı türlerin avcılığının azaltılması ve tür seçiciliği için modifiye ve iyileştirme çalışmalarına katkı sağlayabileceği düşünülmektedir
Distribution on the nets of bycatch fishes caught by multifilament and monofilament trammel nets
In this study, the distribution on the nets of by-catch fish species caught by the trammel nets was determined between 01 January 2002 and 31 December 2002 in the Sinop province shores of Black Sea. Nets have multifilament (Fml) and monofilament (Fmn) material with inner mesh size of 36 mm and outer mesh size of 200 mm, were used in the study. The number (7 meshes) of the outer at the height of the net for vertical position of fish was considered. Buoyancy rope of equipped net was divided 10 equal parts for horizontal position. A total of 286 by-catch fish (Scorpeana porcus, Gaidropsarus mediterraneus, Solea spp., Gobius spp. and Labrus spp., species) were caught in the study. Fml and Fmn were captured 188 and 98 specimens, respectively. For both nets, the fishes showed capture distribution in the bottom parts (1 and 2 no outer net) 76.1% and 77.6% respectively. Fishes with demersal characteristics lower were caught in the middle (3, 4 and 5 no outer net) and upper parts (6 and 7 no outer net) of the nets. It is thought that the results may contribute to the modification and improvement studies in the reduction of none target species in and achieving species selectivity in the trammel net fisheries.
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- Aksu, H. (2006). The effect of using sardon in trammel nets on prevent catching of discarded species (in Aksu, H. (2006). The effect of using sardon in trammel nets on prevent catching of discarded species,. Msc. Thesis, Ondokuz Mayıs University, Samsun, Turkey, 90 p. (In Turkish)
- Angelsen, K. & Olsen, S. (1987). Impact of fish density and effort level on catching efficiency of fishing gear. Fisheries Research, 5(2-3): 271-278.
- Aydın, C., Tosunoğlu, T. & Tokaç, A. (2001). Improvement of size selectivity of bottom trawl nets by using grid systems. Ege Journal of Fisheries and Aquatic Sciences, 18(1-2): 91-101. (In Turkish)
- Balık, İ. (2001). Comparison of sesonal catch per unit efforts for mono-multifilament trammel nets in Lake Beyşehir. Turkish Journal of Fisheries and Aquatic Sciences, 1: 17-21.
- Bjordal, A. (2002). The use of technical measures in responsible fisheries: regulation of fishing gear. A Fishery Manager’s Guidebook - Management Measures and Their Application Chapter 2 ISBN 92-5-10473204, FAO. (ed. Kevern L. Cochrane).
- Ceylan, Y. & Şahin, C. (2019). Selectivity of different alternative cod ends and radial square mesh escape panels (RSEP). Turkish Journal of Fisheries and Aquatic Sciences, 19(6): 451-461.
- Dickson, W. (1989). Cod gillnet effectiveness related to local abundance, availability and fish movement. Fisheries Research, 7(1-2): 127-148.
- Faife, J. R. (2003). Effect of mesh size and twine type on gillnet selectivity of cod (Gadus morhua) in icelandic coastal waters. UNU-Fisheries Training Programme, Final Project.
- Godo, H., Furevik, D. & Lokkeborg, S. (2003). Reduced bycatch of red king crab (Paralithodes camtschaticus) in the gillnet fishery for cod (Gadus moruha) in northern Norway. Fisheries Research, 62: 337–384.
- Gökçe, G. (2004). Research on reduction of non-target species in shrimp trammel net. Ph. D. Thesis, Ege University, İzmir, Turkey, 115 p. (In Turkish)
- Gurbet, R., Alaz, A., Ayaz, A. & Erdem, M. (1998). Research on catch efficiency of gillnets. E.U. Research Fund Project No: 1996 SUF-01 Project Report. (In Turkish)
- Hamley, J. M. (1980). Sampling with Gillnets. FAO Guidelines for Sampling Fish in Inland waters. Eiffac/ T33: 37-55.
- Holst, R., Wileman, D. & Madsen, N. (2002). The effect of twine thickness on the size selectivity and fishing power of baltic cod gill nets. Fisheries Research, 56(3): 303-312.
- Kara, A. & Özekinci, U. (2002). Selectivity of gillnets used in sardine fishing (Sardina pilchardus Walbaum, 1792) in Izmir Bay. Ege Journal of Fisheries and Aquatic Sciences, 19 (3-4): 465-472.
- Kara, A., Çıra, E., Hepgüvendik, N. & Yücel, S. (1994). The confirmation of fish scattering ratios on net and the length/catch ratios in night dawn, dusk and daytimes for catching annular sea bream (Diplodus annularis) by trammel nets in Izmir Bay. Ege University Journal of the Faculty of Science, Seri B(16/1): 1643-1653.
- Lamberts, D. (2001). Tonle sap fisheries: a case study on flood plain gillnet fisheries. RAP Publication 2001/11. FAO, Asia-Pacific Fishery Commission.
- Madsen, N. & Holst, R. (2002). Assessment of the cover effect in trawl codend selectivity experiments. Fisheries Research, 56: 289-301.
- Özbilgin, H., Tokaç, A. & Kaykaç, H. (2012). Selectivity of commercial compared to larger mesh and square mesh trawl codends for four fish species in the Aegean Sea. Journal of Applied Ichthyology, 28(1): 51-59.
- Özdemir, S. & Erdem, Y. (2006). Effect on catchability of species and species selectivity of structure properties and net material of gillnets. Ege Journal of Fisheries and Aquatic Sciences, 23(3-4): 429-433. (In Turkish)
- Özdemir, S. & Erdem, Y. (2007a). Comparison of catch locatıon on trammel nets of dıfferent fısh specıes. Turkish Journal of Aquatic Life, 3-5(3-4): 387-394. (In Turkish)
- Özdemir, S. & Erdem, Y. (2007b). Farklı rüzgar durumlarında kullanılan multifilament ve monofilament fanyalı uzatma ağlarının av verimleri. Fırat Üniversitesi Fen ve Mühendislik Bilimleri Dergisi,19(3): 317-323.
- Özdemir, S., Erdem, Y. & Sümer, Ç. (2003). Farklı materyale sahip fanyalı solungaç ağlarının av verimleri ve av kompozisyonunun karşılaştırılması. XII. Ulusal Su Ürünleri Sempozyumu, Bildiriler Kitabı 1: 467-472.
- Özdemir, S., Özsandıkçı, U., Erdem, Y. Büyükdeveci, F. (2017).Catch composition of crab species that as bycatch captured by trammel nets used on Sinop coasts. Turkish Journal of Maritime and Marine Sciences, 3(2): 55-62. (In Turkish)
- Potter, E. C. E. & Pawson. M. G. (1991). Gill netting. Laboratary Leaflet Number 69. 34 pp.
- Sainsbury, C. J. (1995). Commercial fishing methods. 3rd. Edition. Fishing News Books Ltd. Farnham. 359 p.
- Sümer, Ç. (2003). Farklı materyal ve göz açıklığına sahip solungaç ağlarının av kompozisyonu ve seçiciliği. Yüksek Lisans Tezi, Ondokuz Mayıs Üniversitesi, Samsun, Türkiye, 88s.
- Sümer, Ç., Özdemir, S. & Erdem., Y. (2010). Determination of selectivity monoflament and multiflament gillnets with different mesh size for bluefish (Pomatomus saltatrix L., 1766). Ege Journal of Fisheries and Aquatic Sciences, 27(3): 121-124. (In Turkish)
- Stewart, P. A. M. (1987). The selectivity of slackly hung cod gillnets constructed from three different types of twine. ICES Journal of Marine Science,43(3):189-193.
- Tokaç, A., Özbilgin, H. Kaykaç, M. H. (2010). Selectivity of conventional and alternative codend design for five fish species in the Aegean Sea. Journal of Applied Ichthyology, 26: 403-409.