Mustafa ÇEKİÇ, Gökhan GÖKÇE, Süleyman ÖZDEMİR

Determination of size selectivity of traps for Blue Crab ( callinectes sapidus rathbun, 1896) in the Nediterranean sea

Bu çalışmada mavi yengeç (Callinectes sapidus)in tuzaktan kaçma başarısı üzerinde çeşitli göz açıklığına sahiptuzakların seçicilik etkileri incelenmiştir. Araştırma Akdenizde Yumurtalık körfezi, Çamlık Lagününde yürütülmüşdikdörtgen şekilli yemli tuzaklar kullanılarak toplam 1051 adet mavi yengeç yakalanmıştır. 30, 35, 40, 45 ve 50 mm karegözlü ağ ile donatılmış tuzaklarla her bir tuzaktan kaçan yengeçlerin oranı 0.5 cm lik karapaks genişlik (CW) sınıfındaölçülerek tespit edilmiştir. Denemede her göz açıklığı için tuzaklarda kalan ve kaçan mavi yengeçlerin boy frekans verilerine göre lojistik bir model kullanılmıştır. Araştırmada kullanılan 30, 35, 40, 45 ve 50 mmlik kare gözlü ağların% 50 seçicilik boyu (L50) ve seçicilik aralığı (SR) sırasıyla 8.47 cm ve 0.85 cm; 9.31 cm ve 0.39 cm; 10.40 cm ve 0.31cm; 11.72 cm ve 1.17 cm; 13.17 cm ve 0.89 cm olarak belirlenmiştir. Tuzaktan kaçan ergin olmayan mavi yengeçlerinyüksek oranı ve % 50 cinsi olgunluk boyu dikkate alındığında 50 mmlik kare gözlü ağa sahip tuzak, diğer tuzaklaragöre daha yüksek seçicilik göstermiştir.

Akdenizde Mavi Yengeç ( callinectes sapidus rathbun, 1896) tuzaklarının boy seçiciliğinin belirlenmesi

This study investigates the effects of trap selectivity of various mesh size on escape success of the blue crab (Callinectessapidus). The study was carried out Çamlık Lagoon of Yumurtalık Gulf in the Mediterranean Sea and total of 1051 bluecrabs were caught by rectangular baited trap. Using traps constructed with 30, 35, 40, 45 and 50 mm square mesh theproportion of crabs escaping through each mesh size was measured for each half centimetre carapace width (CW) class.A logistic model was ftted to the size frequency data of the retained and escaped blue crabs for each mesh size in theexperiment. L50 and selection range (SR) for the 30, 35, 40, 45 and 50 mm (bar length) square meshes tested in this studywas 8.47 cm and 0.85 cm; 9.31 cm and 0.39 cm; 10.40 cm and 0.31 cm; 11.72 cm and 1.17 cm; 13.17 cm and 0.89 cmrespectively. The 50 mm square mesh of the trap showed relatively better selectivity considering the size at 50% sexualmaturity of blue crab Callinectes sapidus, and the high rate of immature escapers.

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