Selectivity of standard and narrow trawl codends for the red mullet (Mullus barbatus L., 1758) and annular sea bream (Diplodus annularis L., 1758).
Abstract
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.
Keywords
References
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Details
Primary Language
Turkish
Subjects
-
Journal Section
Research Article
Authors
M. Hakan Kaykaç
Publication Date
September 1, 2007
Submission Date
December 7, 2015
Acceptance Date
-
Published in Issue
Year 1970 Volume: 24 Number: 3