Effect of PA and PE material on codend selectivity in Turkish bottom trawl
Küçük Resim Yok
Tarih
2004
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Bv
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study investigates the differences in the selective properties of a 40 mm nominal PE, 36 and 44 mm nominal PA codends. The experiments were carried out in Izmir Bay in the Eastern Aegean Sea between 4 February 2002 and 22 March 2002. A conventional bottom trawl was operated onboard R/V Egesuf. Selectivity data were collected for red mullet (Mullus barbatus). annular sea bream (Diplodus annularis), picarel (Spicara smaris) and common pandora (Pagellus erythrinus) by using hooped covered codend method. Selectivity parameters were obtained by using logistic equation with the maximum likelihood method and by taking into account between-haul variation. Three codends were tested in a total of 25 hauls of which 18 were accepted valid for picarel and 23 valid for the other three species. In general. the PA material codends produced much higher L-50 values than the PE codend. However, the SRs of the three tested codends, were very close to each other. L-50'S of 40 mm PE, 36 mm PA and 44 mm PA codends, respectively, were found as 8.8. 8.4 and 10.3 cm for annular sea bream; 10.8, 12.4 and 13.8 cm for common pandora. There were not enough red mullet and picarel retained in the 44 min PA codend to estimate the selectivity parameters. Due to insufficient amount of retained fish selection parameters of 44 mm PA codend could not be obtained for red mullet and picarel. L-50'S of PE 40 mm and PA 36 rum codends. respectively, were 10.7 and 12.8 cm for red mullet and 12.4 and 13.3 cm for picarel. It is thought that 40 mm PE netting. which is commercially used, has rather poor selectivity. On the other hand, 44 mm PA codend causes the loss of marketable fish. Amongst the three tested codends 36 mm PA provides the most appropriate selection. (C) 2003 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
polyamide, polyethylene, codend material, selectivity, red mullet, annular sea bream, picarel, common pandora
Kaynak
Fisheries Research
WoS Q Değeri
Q2
Scopus Q Değeri
Q1
Cilt
67
Sayı
3
