Multifilament Gillnet Selectivity for the Red Mullet (Mullus barbatus) in the Eastern Black Sea Coast of Turkey, Trabzon

Year 2008, Volume: 8 Issue: 2, - , 01.04.2008

A. Cemal Dinçer Mustafa Bahar

Abstract

The mesh selectivity of multifilament gillnets for red mullet (Mullus barbatus) was investigated using four different stretched mesh sizes (32, 36, 40 and 44 mm). Experimental fishing operations were carried out in Trabzon (Turkey) coasts of the Black Sea in springtime between 2002 and 2003. Selectivity on M. barbatus was assessed using the SELECT method, implemented in the PASGEAR software. Five different functional models; normal location, normal scale, gamma, log-normal and bi-model were used to fit the selectivity curve to the catch data. It was shown that the bi-model function was the best to fit the data. For the selectivity curves on the bi-model, the optimum lengths (100% retention probability for the 32, 36, 40 and 44 mm mesh sizes) were obtained as 14.24 cm, 16.02 cm, 17.8 cm, and 19.58 cm respectively. Considering the minimum allowable landing size (13 cm) 36 mm was found the most adequate mesh for exploiting the red mullet as it evidenced more conservative approach towards fishing management.

Keywords

Red mullet, gillnet, mesh selectivity, SELECT method, Black Sea

References

• Anonymous. 2004. Fisheries regulation for marine and fresh waters for commercial Şshery, 2004—2006 Şshing period No.236\1, Ministry of Agriculture and Rural Affair of Turkey, Protect and Control General OfŞce,
• A.C. Dinçer and M. Bahar. / Turk. J. Fish. Aquat. Sci. 8: 355-359 (2008) 359
• Ankara, 71 pp. (In Turkish)
• Carol, J. and Garcia-Berthou, E. 2007. Gillnet selectivity and its relationship with body shape for eight freshwater Şsh species. Journal of Applied Ichthyology, 23: 654—660.
• Dos Santos, M.N., Gaspar, M., Monteiro, C.C. and Erzini, K. 2003. Gillnet selectivity for European hake Merluccı'us merluccı'us from southern Portugal: implications for Şshery management. Fish. Sci., 69: 873-882.
• Erzini, K., Gonçalves, J.M.S., Bentes, L., Lino, P.G., Ribeiro, J. and Stergiou, K.I. 2003. Quantifying the roles of competing static gears: comparative selectivity of longlines and monoŞlament gillnets in a multi-species Şshery of the Algarve (southern Portugal). Sci. Mar., 67: 341—352.
• Fabi, G., Sbrana, M., Biagi, F., Grati, F., Leonor, I. and Saıtor, P.S. 2002. Trammel net and gillnet for Lithognathus mormyrus (L. 1758), and Mullus barbatus (L. 1758) in the Adriatic and Lingurian Seas. Fish. Res., 54: 375-388.
• FAO, 2004. FishStat Plus, Universal software for Şshery statistical time series, http://WWW.fao.org/Ş/Website/ FIRetrieveAction.do?dom=topic&Şd=16073&lang=e n (April 20, 2007)
• Fujimori, Y. and Tokai, T. 2001. Estimation of gillnet selectivity curve by maximum likelihood method. Fish. Res., 67: 644—654.
• Hameed, M.S. and Boopendranath, M.R. 2000. Modern Fishing gear Technology. Daya Publishing House. Delhi, India, 186 pp.
• Hamley, J.M. 1975. Review of gillnet selectivity. Board Canada, J. Fish. Res., 32: 1943-1969.
• Kolding, J. 1999. PASGEAR. A data base package for experimental or artisanal Şshery data from passive gears. An introductory manual. University of Bergen, Dept. of Fisheries and Marine Biology. Bergen, Norway, 56 pp.
• Kurkilahti, M., Appelberg, M., Bergstrand, E. and Enderlein, O. 1998. An indirect estimate of bimodal gillnet selectivity of smelt. J. Fish Biol., 52: 243—254.
• Millar, R.B. 1992. Estimating the size selectivity of Şshing gear by conditioning on the total catch. Journal of the American Statistical Association, 87: 962-968.
• Millar, R.B. and Holst, R. 1997. Estimation of gillnet and hook selectivity using log-linear models. ICES J. Mar. Sci., 54: 471-477.
• Millar, R.B. and Fryer, R.J. 1999. Estimating the size- selection curves of towed gears, traps, nets and hooks. Rev. Fish Biol. Fish., 9: 89-116.
• Özbilgin, H., Tosunoğlu, Z., Bilecenoğlu, M. and Tokaç, A. 2004. Population parameters of Mullus barbatus in Izmir Bay (Aegean Sea), using length frequency analysis. J. Appl. Ichthyol., 20: 231-233.
• Park, C.D., Jeong, E.C., Shin, J.K., An, H.C. and Fujimori, Y. 2004. Mesh selectivity of encircling gill net for gizzard shad Konosı'rus punctatus in the coastal sea of Korea, Fisheries Science, 70: 553-560.
• Pet, J.S., Pet-Soede, C. and van Densen, W.L.T. 1995. Comparison of methods for the estimation of gillnet selectivity to tilapia, cyprinids and other Şsh species in a Sri Lankan reservoir. Fish. Res., 24: 141—164.
• Petrakis, G. and Stergio, K.L. 1996. Gillnet selectivity for four Şsh species (Mullus barbatus, Pegallus eryhrinus, Pegallus acerne and Spicare fllexuase) in Greek waters. Fish. Res., 27: 17-27.
• Poulsen, S., Nielsen, J.R., Holst, R. and Staehr, K.J. 2000. An Atlantic herring (Clupea harengus) size selection model for experimental gill nets used in the Sound (ICES Subdivision 23). Can. J. Fish.Aquat. Sci., 57: 1551—1561.
• Samaranayaka, A., Engâs, A. and Jorgensen, T. 1997. Effects of hanging ratio and fishing depth on the catch rates of drifting tuna gillnets in Sri Lankan waters. Fish. Res., 29: 1—12.
• Sbrana, M., Belcari, P., de Ranieri, S., Sartor, P. and Viva, C. 2007. Comparison of the catches of European hake (Merluccı'us merluccı'us, L. 1758) taken with experimental gillnets of different mesh sizes in the northern Tyrrhenian Sea (western Mediterranean), Scientia Marina, 71: 47-56.
• Sparre, P. and Venema, S.C. 1998. Introduction to Tropical Fish Stock Assessment 1: Manual. FAO Fish. Tech. Paper, 306/1 Rev.2. Rome, 407 pp.
• Yokota, K., Fujimori, Y., Shiode, D. and Tokai, T. 2001. Effect of thin twine on gill net size selectivity analysed with the direct estimation method. Fisheries Science, 67: 851-856.