The effects of netting twine on discard rates of commercial red mullet gillnets in Izmir Bay

In this study, discarded rates of the commercial red mullet (Mullus barbatus) gillnets made from different netting twine, monofilament and multifilament were presented. The nets were set near the shore which contains sea grasses (Posidonia oceanica) in İzmir Bay. These areas are sensitive habitats. During the fishing trials, totally 32 fish species have been caught, 21 of which were non-marketable. The rates of these non-marketable species are 77.8% and 22.8% in number for monofilament and multifilament gillnets, respectively. Serranidae and Labridae families were dominant in catch composition. The CPUE of the monofilament and multifilament gillnets for weight were calculated as 129.6±5.1 and 36.9±1.3 respectively. As a result, monofilament gillnets caught more non-marketable species than multifilament gillnets (P<0.05; z=0.007). Because of the high rate of discarded species, it is not advisable to use monofilament gillnets near the shore, which contains sensitive habitats.

Anahtar Kelimeler:

Mullidae, Türkiye

PDF

___

Akyol, O. 2003. Retained and trash fish catches of beachseining in the Aegean Coast of Turkey. Turkish J. of Veterinary and Animal Sci., 27: 1111-1117.

Akyol, O. and Kara, A. 2003. An investigation on the determination of catch compositions of the bottom trawling and beach-seining in the Bay of Izmir Aegean Sea, E.Ü. J. of Fisheries and Aquatic Sci., 20(3-4): 321-328

Alverson, D.L., Freeber, M.H., Murawski, S. and Pope, J.P. 1994. A Global Assesment of Fisheries Bycatch and Discards. FAO Fish. Tech. Pap. No. 339. FAO, Rome, 223 pp.

Andrew, N.L., Jones, T., Terry, C. and Pratt, R. 1995. Bycatch form an Australian stow net fishery for school prawns (Metapenaeus macleayi). Fisheries Research, 22: 119-136.

Anonymous. 1999. Fisheries regulation for marine and fresh waters for commercial fishery, 1999-2000 fishing period No.:331, Ministry of Agriculture and Rural Affair of Turkey, Protect and Control General Office, Ankara, 71 pp. (in Turkish).

Aydın, C., Kaykaç, H. and Tokaç, A. 2004 Application of double grid systems in Turkish traditional trawl fisheries. E.Ü. J. of Fisheries and Aquatic Sci., 22(1 2): 43-48.

Aydın, C. and Tosunoğlu, Z. 2004. Sorting grids in trawl. E.Ü. J. of Fisheries and Aquatic Sci., 23:(1-2): 235- 238.

Aydın, İ., Gökçe, G. and Metin, C. 2006. The effects of monoflament and multiflament PA netting twine on catch composition of the red mullet gillnets. E.Ü. J. of Fisheries and Aquatic Sci., 23:(3-4): 285-289.

Aydın, İ. and Metin, C. 2008. Effects of time of the day on catch composition in monofilament and multifilament gillnets fishing. Journal of Fisheries Sciences.com, 2: 608-615 (in Turkish).

Dutt, S. 1965. An interpretation of the data from the effect of mesh size on the fishing efficiency of sardine gillnets. Fishing Technology, 11(2): 249-250.

Fabi, G., Sbarana, M., Biogi, F., Grati, F., Leonori, I. and Sartor, P. 2002. Trammel net and gillnet selectivity for Lithognatus mormyrus (L., 1758), and Mullus barbatus (L., 1758) in the Adriatic and Lingurian seas. Fisheries Research, 54: 375-388.

Godøy, H., Furevik, D. and Løkkeborg, S. 2003. Reduced bycatch of red king crab (Paralithodes camtschaticus) in the gillnet fishery for cod (Gadus morhua) in northern Norway. Fisheries Research, 62: 377-384.

Gökçe, G. 2004. Research on reduction of non-target species in shrimp trammel net. PhD. thesis, Izmir: Ege University. (in Turkish).

Gökçe, G. and Metin, C. 2007. Landed and discarded catches from commercial prawn trammel net fishery. Journal of Applied Ichthyology, 23: 543-546.

Kelleher, K. 2005. Discards in the world’s marine fisheries. FAO Fisheries Technical Paper, Rome, 470 pp.

Kınacıgil, H.T., Çıra, E. and İlkyaz, A. 1999. By-catch problems in fisheries and preliminary study. E.Ü. J. of Fisheries and Aquatic Sci., 16(3-4): 437-444.

Metin, C., Lök, A. and İlkyaz, A.T. 1998. The selectivity of gill net in different mesh size for Diplodus annularis (L., 1758) and Spicara flexuosa (Rafinesque, 1810). E.Ü. J. of Fisheries and Aquatic Sci., 15(3-4): 293 303.