Selectivity of standard and narrow trawl codends for the red mullet (Mullus barbatus L., 1758) and annular sea bream (Diplodus annularis L., 1758).
Öz
The bottom trawl codends (40 mm PE) used in conventional Turkish demersal fisheries has rather poor selectivity. For this reason, the improvements of the codend selectivity in the bottom trawl nets get importance from the point of view to protect of demersal fish stocks. In this study, selectivity properties of standard codend (200 meshes around the circumference) conventionally used in Turkish bottom trawl fisheries and narrow codend (100 meshes instead of 200 meshes around the circumference) had been searched for red mullet (Mullus barbatus) and annular sea bream (Diplodus annularis) in the Aegean Sea. Sea trials were carried out in İzmir Bay between 3rd June and 27th July 2004 on board R/V “Egesüf”. Data were collected using the covered codend technique, and analyzed by means of a logistic equation with the maximum likelihood method. For the red mullet, it was shown that the narrow codend (L50=13.9 cm) was higher an average L50 values than the standard codend (L50=11.8 cm). However, there was no significant difference between average L50 values of the codends for the annular sea bream (p>0.05). As a consequence, it was determined that the narrowed codend compared to standard codend provided considerable improvements for the selectivity of red mullet.
Anahtar Kelimeler
Standard codend narrowed codend trawl selectivity hopped covered codend
Kaynakça
- Armstrong, D.W., R.S.T. Ferro, D.N. Maclennan, and S.A. Reeves. 1990. Gear selectivity and the conservation of fish. Journal of Fish Biology, 37: 261-262.
- Bahamon, N., F. Sardà, and P. Suuronen. 2006. Improvement of trawl selectivity the NW Mediterranean demersal fishery by using a 40 mm square mesh codend. Fish. Res., 81: 15-25.
- Broadhurst, M. K., and S. J. Kennelly. 1996. Effects of the circumference of codends and a new design of square-mesh panel in reducing unwanted bycatch in the New South Wales oceanic prawn-trawl fishery. Australia. Fish. Res., 27: 203–214.
- Efanov, S.F., I.G. Istomin, and A.A. Delmatov. 1987. Influence of the form of fish body and mesh on selective properties of trawls. ICES C.M. B:13: 22.
- Fiorentini, L., and I. Leonori. 2002. The effect of mesh size and number of meshes around the cod-end on red mullet and hake selectivity. ICES FTFB Working Group Meeting, 6-8 June 2002, Sete, France.
- Lök, A., A. Tokaç, Z. Tosunoğlu, C. Metin, and R.S.T. Ferro. 1997. The effects of different cod-end design on bottom trawl selectivity in Turkish fisheries of the Aegean Sea. Fish. Res., 32:149-156.
- Metin, G. and O. Akyol. 2003. A preliminary study onthe determination of batch fecundity of annular se bream (Diplodus annularis L., 1758) in Izmir Bay (Aegean Sea)(in Turkish). Journal of Fisheries and Aquatic Sciences. Volume:20, Issue 1-2: 205-209.
- Özbilgin, H., Z. Tosunoğlu, C. Aydın, M.H. Kaykaç, and T. Tokaç. 2005. Selectivity of standard, narrow and square mesh panel trawl codends for hake (Merluccius merluccius) and poor cod (Trisopterus minutus capelanus). Türk. J. Vet. Anim. Sci., 29: 967-973.
- Petrakis, G., and K.I. Stergiou. 1997. Size selectivity of diamond and square mesh codends for four commercial Mediterranean fish species. ICES Journal of Marine Science, 53: 1323.
- Prado, J. and P.Y. Dremière. 1990. Fisherman’s Workbook. Fishing News Boks, Osney Mead, Oxford OX2 0EL, England, 178.
- Reeves, S.A., D.W. Armstrong, R.J. Freyer, and K.A. Coul. 1992. The effects of mesh size, cod-end extension length and cod-end diameter on the selectivity of Scottish trawls and seines. ICES J. Mar. Sci., 49: 279-288.
- Robertson, J.H.B. and R.S.T. Ferro. 1988. Mesh selection within the cod-end of trawls. The effects of narrowing the cod-end and shortening the extension, Scot. Fish. Res. Report No 39, 11.
- Stewart, P. 2002. A review of studies of fishing gear selectivity in the Mediterranean. COPEMED. Number, 9: 56.
- TKB-KKGM, 2004. The commercial fish catching regulations in seas and inland waters in 2004-2006 fishing period (in Turkish). Circular No. 36/1. Ministry of Agriculture and Rural Affairs (MARA), Ankara, 86s.
- Tokai, T. 1997. Maximum likelihood parameter estimates of a mesh selectivity logistic model through SOLVER on MS-Excel, Bull. Jpn. Fish. Oceanogra., 61:288-298.
- Tokaç, A., A. Lök, Z. Tosunoğlu, C. Metin, and R.S.T. Ferro. 1998. Codend selectivities of a modified bottom trawl for three fish species in the Aegean Sea. Fish. Res., 39:17-31.
- Tokaç, A., H. Özbilgin and M.H. Kaykaç. 2006. Selectivity of commercial and new design trawl codends in the Eastern Mediterranean. Fishing Technology in the 21st Century: Integrating Fishing and Ecosystem Conservation. ICES 2006 Boston, USA. 122-123.
- Tosunoğlu, Z., Y.D., Özbilgin, and H., Özbilgin. 2003. Body shape and trawl codend selectivity for nine commercial fish species. J. Mar. Biol Aassoc., UK 83 (6): 1309-1313.
- Tosunoğlu, Z. 1998. Structural modifications to improve cod-end selectivity at the bottom trawl nets used in Turkish Seas. Thesis of Ph.D., Department of Fisheries and Processing Technology (in Turkish). Bornova-İzmir. 121.
- Wileman, D.A., R.S.T. Ferro, R. Fonteyne, and R.B. Millar. 1996. Manual of Methods of Measuring the Selectivity of Towed Fishing Gears. ICES Cooperative Research Report No. 215: 126.
Barbunya (Mullus barbatus L., 1758) ve Isparoz (Diplodus annularis L., 1758) İçin Standart ve Dar Trol Torbaların Seçiciliği
Öz
Türkiye’deki, demersal balıkçılıkta kullanılan dip trol torbaları (40 mm PE) düşük seçicilik özelliğindedir. Bu yüzden dip trol ağlarında torba seçiciliğinin geliştirilmesi demersal balık stoklarının korunması bakımından önem kazanmaktadır. Bu çalışmada Ege Denizi’nde barbunya (Mullus barbatus) ve ısparoz (Diplodus annularis) balık türlerine ait, Türkiye dip trol balıkçılığında ticari olarak kullanılan standart torba (çevre göz sayısı 200) ve dar torbanın (çevresinde 200 göz yerine 100 göz olan) seçicilik özellikleri araştırılmıştır. Deniz çalışmaları İzmir Körfezinde 3 Haziran ve 27 Temmuz 2004 tarihleri arasında araştırma gemisi “Egesüf” ile yürütülmüştür. Veriler örtü torba tekniği kullanılarak elde edilmiş ve ‘En Yüksek Olabilirlik Yöntemi’ ile lojistik denklem kullanılarak analiz edilmiştir. Dar torba (L50=13,9 cm), barbunya için standart torbadan (L50=11,8 cm) daha yüksek bir ortalama L50 değeri göstermiştir. Buna karşın, Isparoz için torbaların ortalama L50 değerleri arasında önemli bir fark yoktur (p>0,05). Sonuç olarak, daraltılmış torba standart torba ile karşılaştırıldığında barbunya seçiciliğinde önemli iyileştirmeler sağladığı tespit edilmiştir
Anahtar Kelimeler
Standard torba dar torba trol seçiciliği çemberli örtü torba
Kaynakça
- Armstrong, D.W., R.S.T. Ferro, D.N. Maclennan, and S.A. Reeves. 1990. Gear selectivity and the conservation of fish. Journal of Fish Biology, 37: 261-262.
- Bahamon, N., F. Sardà, and P. Suuronen. 2006. Improvement of trawl selectivity the NW Mediterranean demersal fishery by using a 40 mm square mesh codend. Fish. Res., 81: 15-25.
- Broadhurst, M. K., and S. J. Kennelly. 1996. Effects of the circumference of codends and a new design of square-mesh panel in reducing unwanted bycatch in the New South Wales oceanic prawn-trawl fishery. Australia. Fish. Res., 27: 203–214.
- Efanov, S.F., I.G. Istomin, and A.A. Delmatov. 1987. Influence of the form of fish body and mesh on selective properties of trawls. ICES C.M. B:13: 22.
- Fiorentini, L., and I. Leonori. 2002. The effect of mesh size and number of meshes around the cod-end on red mullet and hake selectivity. ICES FTFB Working Group Meeting, 6-8 June 2002, Sete, France.
- Lök, A., A. Tokaç, Z. Tosunoğlu, C. Metin, and R.S.T. Ferro. 1997. The effects of different cod-end design on bottom trawl selectivity in Turkish fisheries of the Aegean Sea. Fish. Res., 32:149-156.
- Metin, G. and O. Akyol. 2003. A preliminary study onthe determination of batch fecundity of annular se bream (Diplodus annularis L., 1758) in Izmir Bay (Aegean Sea)(in Turkish). Journal of Fisheries and Aquatic Sciences. Volume:20, Issue 1-2: 205-209.
- Özbilgin, H., Z. Tosunoğlu, C. Aydın, M.H. Kaykaç, and T. Tokaç. 2005. Selectivity of standard, narrow and square mesh panel trawl codends for hake (Merluccius merluccius) and poor cod (Trisopterus minutus capelanus). Türk. J. Vet. Anim. Sci., 29: 967-973.
- Petrakis, G., and K.I. Stergiou. 1997. Size selectivity of diamond and square mesh codends for four commercial Mediterranean fish species. ICES Journal of Marine Science, 53: 1323.
- Prado, J. and P.Y. Dremière. 1990. Fisherman’s Workbook. Fishing News Boks, Osney Mead, Oxford OX2 0EL, England, 178.
- Reeves, S.A., D.W. Armstrong, R.J. Freyer, and K.A. Coul. 1992. The effects of mesh size, cod-end extension length and cod-end diameter on the selectivity of Scottish trawls and seines. ICES J. Mar. Sci., 49: 279-288.
- Robertson, J.H.B. and R.S.T. Ferro. 1988. Mesh selection within the cod-end of trawls. The effects of narrowing the cod-end and shortening the extension, Scot. Fish. Res. Report No 39, 11.
- Stewart, P. 2002. A review of studies of fishing gear selectivity in the Mediterranean. COPEMED. Number, 9: 56.
- TKB-KKGM, 2004. The commercial fish catching regulations in seas and inland waters in 2004-2006 fishing period (in Turkish). Circular No. 36/1. Ministry of Agriculture and Rural Affairs (MARA), Ankara, 86s.
- Tokai, T. 1997. Maximum likelihood parameter estimates of a mesh selectivity logistic model through SOLVER on MS-Excel, Bull. Jpn. Fish. Oceanogra., 61:288-298.
- Tokaç, A., A. Lök, Z. Tosunoğlu, C. Metin, and R.S.T. Ferro. 1998. Codend selectivities of a modified bottom trawl for three fish species in the Aegean Sea. Fish. Res., 39:17-31.
- Tokaç, A., H. Özbilgin and M.H. Kaykaç. 2006. Selectivity of commercial and new design trawl codends in the Eastern Mediterranean. Fishing Technology in the 21st Century: Integrating Fishing and Ecosystem Conservation. ICES 2006 Boston, USA. 122-123.
- Tosunoğlu, Z., Y.D., Özbilgin, and H., Özbilgin. 2003. Body shape and trawl codend selectivity for nine commercial fish species. J. Mar. Biol Aassoc., UK 83 (6): 1309-1313.
- Tosunoğlu, Z. 1998. Structural modifications to improve cod-end selectivity at the bottom trawl nets used in Turkish Seas. Thesis of Ph.D., Department of Fisheries and Processing Technology (in Turkish). Bornova-İzmir. 121.
- Wileman, D.A., R.S.T. Ferro, R. Fonteyne, and R.B. Millar. 1996. Manual of Methods of Measuring the Selectivity of Towed Fishing Gears. ICES Cooperative Research Report No. 215: 126.
Ayrıntılar
| Birincil Dil | Türkçe |
|---|---|
| Bölüm | Makaleler |
| Yazarlar | |
| Yayımlanma Tarihi | 1 Eylül 2007 |
| Gönderilme Tarihi | 7 Aralık 2015 |
| Yayımlandığı Sayı | Yıl 2007Cilt: 24 Sayı: 3 |