SÜLEYMAN ÖZDEMİR, YAKUP ERDEM

Uzatma ağlarının ağ materyali ve yapısal özelliklerinin türlerin yakalanabilirliği ve tür seçiciliği üzerindeki etkisi

Bu araştırmada, monofilament ve multifilament materyale sahip fanyalı ve sade uzatma ağlarının av kompozisyonu, türlerin yakalanabilirliği ve tür seçiciliği karşılaştırılmıştır. Denemelerde kullanılan ağların göz açıklığı 36 mm dir. Türlerin % 58,81’i monofilament, % 41,19’u multifilament ağlarla yakalanmıştır. Monofilament ağlarla yakalananların % 95,84’ü, multifilamentlerin ise % 92,67’sinin ekonomik olduğu bulunmuştur. Tüm ekonomik türler içerisinde multifilament ağların payı % 40,38, monofilament ağların payı ise % 59.62 olarak tespit edilmiştir. Hem avlanan balık miktarı hem de hedef tür yakalama oranı yönünden sade ağların fanyalı ağlara oranla daha verimli olduğu belirlenmiştir. Hedef türleri oluşturan istavrit (Trachurus trachurus, L. 1758), barbunya (Mullus barbatus ponticus, E., 1927) ve mezgit (Merlangius merlangus euxinus, N. 1840) balıkların boy kompozisyonları incelendiğinde; sade ağların fanyalı ağlara, multifilament ağların monofilament ağlara göre daha (p

Anahtar Kelimeler:

balık avlama ekipmanı, seçicilik, balık avlama, av kompozisyonu (balık)

Effect on catchability of species and species selectivity of structure properties and net material of gillnets

In this study the catch composition, species selectivity and catchability of species catch of set nets having monofilament and multifilament material were compared. Nets used on experiments have 36 mm mesh. More fish (58,81 %) caught by monofilament net of important portion of fishes (95,84 %), including economical species of less portion of fishes (92,67 %) fished by multifilament nets (41,19 %) were determined. The portion monofilament and monofilament in completely economical species were calculated 40,38 %, 59,62 % respectively. Gillnets more effective than trammel nets viewpoint both fished fishes amount and target species catch ratio were established. Gillnets more be selective (p<0,05) than trammel nets were considered at the length composition of horse mackerel (Trachurus trachurus, L. 1758), red mulled (Mullus barbatus ponticus, E., 1927) and whiting (Merlangius merlangus euxinus, N. 1840) including target species were investigated. Mostly, increasing of bycatch amount more active than excess of total catch for profitable and continuing fishing were designated and as the results using of monofilament and gillnet in fishing of target species is more appropriate were concluded.

Keywords:

fishing gear, selectivity, fishing, catch composition,

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Aksu, H., 2006. The effect of using sardon in trammel nets on prevent catching of discarded species, (in Turkish). Ondokuz Mayıs University Natural Science Institue, Msc. Thesis, 90 p. Samsun.

Anonymus, 2006. Türkiye Statistical Society, Fisheries statistics 2004, (in Turkish).

Balık, İ., 2001. Comparison of sesonal catch per unit efforts for monomultifilament trammel nets in Lake Beyşehir. Turkish Journal of Fisheries and Aquatic Science 1: 17-21 p.

Clucas, I., 1997. A study of the options for utilisation of by-catch and discards from marine capture fisheries, FAO Fish. Cir. No: 928 FIIU/C 928 Food and Agriculture Organisation of the United Nations Rome.

Engas, A., S. Lokkeborg, 1994. Abundance estimation using gillnet and longline. In The Role of Fish Behaviour Marine Fish Behaviour in Capture and Abundance Estimation. Chapter 8, pp.130-163. Ed. By A. Fernö and S. Olsen. Fishing New Boks, London.

Erkoyuncu, İ., 1995. Fisheries biology and population dynamics, (in Turkish). Ondokuz Mayıs University Book, Number: 35, 265 p. Samsun

Fernö, A., S. Olsen, 1994. Marine fish behaviour in capture and abundance estimation. Fishing News Books, 224 p. Published 1994. ISBN 0-85238- 211-1 London.

Godoy, H., D. Furevik, S. Lokkeborg, 2003. Reduced bycatch of red king crab in gillnet fishery for Cod (Gadus morhua) in Northern Norway. Fisheries Research 62: 337-384 pp.

Gökçe, G., 2004. Research on reduction of non-target species in shrimp trammel net, (in Turkish). Ege University Natural Science Institue, Phd Thesis, 115 p. Izmir.

Gurbet, R., A. Alaz, A. Ayaz, M. Erdem, 1998. Research on catch efficiency of gillnets, (in Turkish). E.U. Research Fund Project No: 1996 SUF-01 Project Report.

Hylen, A., T. Jacobsen, 1979. A fishing experiment with multifilament, monofilament and monotwine gillnets. In The Role of Fish Behaviour Marine Fish Behaviour in Capture and Abundance Estimation. . Ed. By A. Fernö and S. Olsen. Fishing New Books, London. Published 1994. ISBN 0-85238-211-1

Millner, R.S., 1985. The use of anchored gill and tangle nets in the sea fisheries of England and Wales. Laboratory Leaflet No:57 Lowesoft.

Özdemir, S., Y. Erdem, 2006. The comparasion of catch efficiency of mono and multifilament gillnets on different weather conditions, (in Turkish). Science and Engineering Journal of Fırat University, 18(1): 63-68 p. Elazığ.

Özdemir, S., Ç. Sümer, Y. Erdem, 2003. Comparison of catch compositon and catch efficiency of trammel nets which have different material, (in Turkish). XII. National Fisheries Symposium, Announcements Book, 467- 472 pp. Elazığ-Türkiye.

Potter, E.C.E., M.G. Pawson, 1991. Gill netting. Ministry of Agriculture, Fisheries and Food Directorate of Fisheries Research, Laboratory Leaflet, Number 69: 1-35 p.

Rudstam, L.G., J.J. Magnuson, W.M. Tonn, 1984. Size selectivity of passive fishing gear: A corection for encounter probability applied to gillnets. Can. J. Fish. Aquat. Sci. 41:1252-1255 p.