The catch amount of Mediterranean horse mackerel Trachurus mediterraneus (Steindachner, 1868) gillnets in the Sea of Marmara

Yıl 2024, Cilt: 26 Sayı: 2, 495 - 506, 15.07.2024

Yusuf Şen , Ceyda Kalemli , Uğur Özekinci

https://doi.org/10.25092/baunfbed.1429833

Öz

The small-scale fishermen in the coastal area of the Marmara Sea between April and June caught the Mediterranean horse mackerel Trachurus mediterraneus (Steindachner, 1868) with gillnets. This target species, T.mediterraneus and significant amounts of non-target species are caught in these nets. So, the technical and structural characteristics of the gillnets for a commercial fishermen were determined and the target and non-target species were evaluated in catching operations. The multifilament gillnet mesh size of 18 milimeters polyamid, twine thickness of 210d/2, hanging ratio of 0.33 and the total length of approximately 200 meters. Also, guarding nets were added to gillnets. The total amount was determined as 397.8 kilograms (kg) and 9204 individuals (ind). The weight of T.mediterraneus was constituted 39.3% of the total weight. The in of T.mediterraneus was constituted 43.4% of the total ind. While the catch per unit effort (CPUE) for T.mediterraneus was calculated at 0.026 kg/m.operation-1 and 0.7 ind/m.operation-1, the CPUE for the total amount was calculated at 0.066 kg/m.operation-1 and 1.5 ind/m.operation-1. The total economic value was calculated at 15814.4 Turkish Liras (TL), which 9390 TL from T.mediterraneus and 6424.4 TL from non-target species. This study is important in terms of revealing for the first time the catch efficiency of gillnets used by commercial fishermen to catch T.mediterraneus in the coastal area of the Marmara Sea, which is an important fishing area. These results will contribute to the creation of management plans and fisheries management for species-specific fishing gear used in a region.

Anahtar Kelimeler

Coastal area, target species, non-targeting species, fisheries management, economic value

Destekleyen Kurum

This study was supported by TUBITAK 2209-A University Students Research Projects with application number 1919B012300624.

Proje Numarası

This study was supported by TUBITAK 2209-A University Students Research Projects with application number 1919B012300624.

Teşekkür

This study was supported by TUBITAK 2209-A University Students Research Projects with application number 1919B012300624. The authors grateful to captain Ahmet ŞEN of Yusuf Kaptan 17 fishing boat for providing the fishing operations. The study was presented as oral presentation at “The 2nd International Conference and the 4th National Conference on Marine Sustainable Development” in Iranian.

Marmara Denizi’nde sarıkuyruk istavrit Trachurus mediterraneus (Steindachner, 1868) uzatma ağlarının av miktarı

Öz

Marmara Denizi’nde gırgır balıkçılığının yasak olduğu Nisan ve Haziran ayları arasında, kıyısal alanda küçük ölçekli balıkçılar uzatma ağları ile sarıkuyruk istavrit Trachurus mediterraneus (Steindachner 1868) avcılığı gerçekleştirmektedir. Bu avcılıkta hedef türün istavritin yanında, önemli miktarlarda hedefdışı türlerde avlanmaktadır. Bunun için Marmara Denizi’nde ticari bir balıkçının istavrit avcılığında kullandığı uzatma ağlarının teknik özellikleri belirlenerek, avcılık operasyonlarında yakalanan hedef ve hedefdışı türler değerlendirilmiştir. Çalışmada kullanılan multifilament uzatma ağının göz genişliği 18 mm, ip kalınlığı 210d/2, donam faktörü 0,33 ve ağın toplam uzunluğu ise yaklaşık 200 metre olarak belirlenmiştir. Ayrıca, uzatma ağlarının alt kısmına sardon ağı ilave edildiği belirlenmiştir. Avcılık operasyonlarında hedef tür istavritin yanında 29 hedef dışı türde yakalandığı tespit edilmiştir. Yakalanan hedef ve hedefdışı türlere ait toplam av miktarının 397,8 kg ve 9204 adet olduğu belirlenmiştir. Hedef tür T.mediterraneus’un ağırlık olarak toplam avın 156,5 kg’sini (%39,3) oluşturduğu belirlenmiştir. Birey sayısı olarak ise 3997 adet T.mediterraneus, toplam avın %43,4’ünü oluşturmaktadır. Birim çabaya düşen av miktarı (CPUE) T.mediterraneus için ağırlık olarak 0,026 kg/m.operasyon-1, adet olarak ise 0,7 adet/m.operasyon-1 hesaplanmıştır. Toplam avda ise ağırlık olarak 0,066 kg/m.operasyon-1, birey sayısı olarak 1,5 adet/m.operasyon-1 hesaplanmıştır. Uzatma ağları ile T. mediterraneus hedeflenen bu avcılıkta hedef türden 9390 TL (%59,4), hedefdışı ticari olarak değerlendirilebilen türlerden ise 6424,4 TL (%40,6) olmak üzere toplam 15814,4 TL kazanç sağlanabileceği hesaplanmıştır. Bu çalışma önemli bir balıkçılık alanı olan Marmara Denizi’nin kıyısal alanında ticari balıkçıların T. mediterraneus türünü avlamak için kullandıkları uzatma ağlarının av veriminin ilk kez ortaya konması bakımından önem taşımaktadır. Bu sonuçların türe özgü kullanılan av araçlarının yönetim planlarının oluşturmasına ve balıkçılık yönetimine katkı sağlayacağı düşünülmektedir.

Anahtar Kelimeler

Kıyısal alan, hedef tür, hedefdışı tür, balıkçılık yöntemi, ekenomik değer

Etik Beyan

Yukarıda bilgileri yer almakta olan çalışmamın/çalışmamızın Orman ve Su İşleri Bakanlığı’nın 2014 yılındaki HAYVAN DENEYLERİ ETİK KURULLARININ ÇALIŞMA USUL VE ESASLARINA DAİR YÖNETMELİ’ğinin (Sayı:28914) 8. Maddesine ölü balıklarda sadece toplam ağırlık ölçümü yapılması, Madde 10’a göre herhangi bir canlı hayvan ile çalışılmaması, Madde 11.’e göre bir deney hayvanı olmaması ve ölü balıklara herhangi bir kimyasal işlem uygulanmamasısebepleriyle etik kurul izni gerektirmeyen çalışmalar arasında yer aldığını beyan ederim/ederiz.

Proje Numarası

This study was supported by TUBITAK 2209-A University Students Research Projects with application number 1919B012300624.

Kaynakça

• Sinclair, M., and Valdimarsson, G., Responsible fisheries in the marine ecosystem in Cook, R., Impact of By-catch mortality by Fishing Gear, Food and Agriculture Organization of the United Nations, Rome, Italy, CABI Publishing, (2003).
• Alverson, D. L., Freeberg, M. H., Murawski, S. A. and Pope, J. G., A global assessment of fisheries bycatch and discards, 339, Food and Agriculture Organization of the United Nation, Rome, Italy, 233 p, (1994).
• Zeller, D., Cashion, T., Palomares, M. and Pauly, D., Global marine fisheries discards: A synthesis of reconstructed data, Fish and Fisheries, 19, 1, 30-39, (2018).
• Tsagarakis, K., Palialexis, A. and Vassilopoulou, V., Mediterranean fishery discards: review of the existing knowledge. ICES Journal of Marine Science, 71, 5, 1219–1234, (2013).
• Gillett, R., Global study of shrimp fisheries, 475, Food and Agriculture Organization of the United Nation Fisheries Technical Paper, 25-29, (2008).
• Bayhan, Y. K., Çiçek, E., Ünlüer, T. and Akkaya, M., Catch and by-catch composition of the shrimp fishery by beam trawl in the southeastern Marmara Sea. Ege Journal of Fisheries and Aquatic Sciences, 23, 3, 277-283, (2006).
• Bozaoğlu, A. S., Akkuş, M. and Eryaşar, A. R., Catch Composition and By-Catch of Commercial Trammel Nets for Cuttlefish (Sepia officinalis, Linné, 1758) in Mersin Bay (north-eastern Mediterranean). Journal of Anatolian Environmental and Animal Sciences, 7, 2, 122-127, (2022).
• Soyer, M. F., Analyzing the bottom trawl fisheries as targetted and untargetted catch in Unye (Ordu) – Terme (Samsun) trawling area, Master’s Thesis, Ordu University, Institute of Natural and Applied Sciences, Department of Fisheries Technology Engineering, Ordu, 2018.
• Cochrane, K. L. Fishery manager’s guidebook, management measures and their application, 424, Food and Agriculture Organization of the United Nation Fisheries Technical Paper, Rome, Italy, 223 p, (2002).
• Da Ros, Z., Fanelli, E., Cassatella, S., Biagiotti, I., Canduci, G., Menicucci, S., de Felice, A., Malavolti, A. and Leonori, I., Resource Partitioning among “Ancillary” Pelagic Fishes (Scomber spp., Trachurus spp.) in the Adriatic Sea. Biology, 12, 2, 272, (2023).
• Demir, M., Sarı kuyruk istavrit balığı (Trachurus mediterraneus LUTKEN, 1880)’nın üremesi hakkında. I- Karadenizde, Hidrobiologi Mecmuası, Seri: A, IV (3-4), 94-102, (1958).
• Demir, N. Karadeniz populasyonuna ait Trachurus mediterranesus LTKN. (Sarıkuyruk istavrit balığı) yumurta ve larvalarının morfolojik hususiyetleri hakkında. Hidrobiologi Mecmuası, Seri: A, IV (3-4), 85-92, (1958).
• Doyuk, S. A., Determination of the technical specifications of fishing gears used in Çanakkale Region, Master’s Thesis, Çanakkale Onsekiz Mart University, Institute of Natural and Applied Sciences, Çanakkale, (2006).
• Emirbuyuran, Ö. and Çalık, S., Technical Characteristics of Drag Nets and Surrounding Nets Used in The Region of Samsun-Ordu-Giresun. Anadolu University Journal of Science and Technology–C Life Sciences and Biotechnology, 4, 2, 49-56, (2016).
• Nedelec, C., FAO Catalogue of Small-Scale Fishing Gear, Fishing News Ltd. Surrey, England, 191, (1975).
• Nomura, M., and Yamazaki T., Fishing Techniques, Japan International Cooperation Agency, Tokyo, 39-125, (1975).
• FAO., FAO Catalogue of Fishing Gear Designs, Fishing News Books Ltd. FAO Fisheries and Technical Paper, England, 160, (1978).
• Bilecenoğlu, M., Kaya, M., Cihangir, B. and Çiçek, E., An updated checklist of the marine fishes of Turkey. Turkish Journal of Zoology, 38, 6, 901-929, (2014).
• Whitehead, P. J. P., Bauchot, M. L., Hureau, J. C., Nielsen J. and Tortonese, E., Fishes of the North-eastern Atlantic and the Mediterranean, Paris, UNESCO, Vol I, II, III, 1-1473, (1986).
• WORMS., World Register of Marine Species, (2023). https://www.marinespecies.org/ (20.06.2023).
• Balık, İ., and Çubuk, H., Catching efficiency of gillnets on capture of some fish species in Lake Uluabat. Ege Journal of Fisheries and Aquatic Sciences, 18, 3-4, 399-405, (2001).
• Hyvärinen, P. and Salojärvi. K., The applicability of catch per unit effort (CPUE) statistics in fisheries management in Lake Dulujärvi, Northern Finland in Cowx I. G., Catch Effort Sampling Strategies, Fishing News Books, Oxford, UK, 241-261, (1991).
• Gökçe, G., Research on reduction of non-target species in shrimp trammel net, Doctoral thesis, Ege University, Institute of Natural and Applied Sciences, İzmir, (2004).
• Aksu, H., The effect of using sardon in trammel nets on prevent catching of discorded species, Master’ Thesis, Ondokuz Mayıs University, Institute of Natural and Applied Science, Fisheries Catching and Processing Technology Department, (2006).
• Yokota, K., Fujimori, Y., Shıode, D. and Tokai, T., Effect of thin twine on gill net size-selectivity analyzed with the direct estimation method. Fisheries Science, 67, 851-856, (2001).
• Ayaz, A., Altinagac, U., Ozekinci, U., Ozen, O., Altın, A. and Ismen, A. Effect of twine thickness on selectivity of gillnets for bogue, Boops boops, in Turkish waters. Mediterranean Marine Science, 12, 2, 358-36, (2011).
• Dereli, H., Kebapçıoğlu, T., Şen, Y., Ölçek, Z. S., Dinçtürk, E. and Ulman, A., The effect of gillnet twine thickness on catching efficiency and selectivity for common carp (Cyprinus carpio Linnaeus, 1758) fishery in Marmara Lake. Ege Journal of Fisheries and Aquatic Sciences, 39, 2, 88-96, (2022).
• Özdemir, S. and Erdem, Y., 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, 429-433, (2006).
• Yıldız, T. and Karakulak, F. S., Technical characteristics of demersal set nets, used in Istanbul artisanal fisheries. Ege Journal of Fisheries and Aquatic Sciences, 27, 1, 19-24, (2010).
• Akyol, O. and Perçin, F., The coastal fisheries and problems in Tekirdağ Province (Marmara Sea). Ege Journal of Fisheries and Aquatic Sciences, 23, 3, 423-426, (2006).
• Erdem, Y., Özdemir, S., Özsandıkçı, U. and Büyükdeveci, F., Technical plans of fishing gears used in the central Black Sea coastal fisheries (Sinop-Samsun). Marine and Life Sciences, 2, 2, 85-96, (2020).
• Dickson, W., Cod gillnet effectiveness related to local abundance, availability and fish movement. Fisheries Research, 7, 1-2, 127-148, (1989).
• Engas, A., Abundance estimation using bottom gillnet and longline the role of fish behaviour, Marine Fish Behaviour in Capture and Abundance Estimation. Fishing News Books, Oxford, UK, 134-160, (1994).
• Kitahara, T., On selectivity curve of gill-net. Bulletin of the Japanese Society of Scientific Fisheries, 37, 4, 289-296, (1971).
• Millner, R. S., The use of anchored gill and tangle nets in the sea fisheries of England and Wales, Ministry of Agriculture, Fisheries and Food, Directorate of Fisheries Research, Laboratory Leaflet No:57 Lowesoft, (1985).
• Brinkhof, I., Herrmann, B., Larsen, R. B., Brinkhof, J., Grimaldo, E. and Vollstad, J., Effect of gillnet twine thickness on capture pattern and efficiency in the Northeast-Arctic cod (Gadus morhua) fishery. Marine Pollution Bulletin, 191, 114927, (2023).