Mesh Selectivity of Drift Gillnet for Caranx sexfasciatus and Caranx tille
Mesh Selectivity of Drift Gillnet for Caranx sexfasciatus and Caranx tille
Date
2010
Authors
Balasubramanian, A.
Meenakumari, B.
Boopendranath, M. R.
Pravin, P.
. Erzini, K.
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Fisheries Technologists (India)Cochin
Abstract
The gear selectivity and fishing power of different mesh sizes (13.5, 14, 14.5 and 15
cm) were investigated using experimental catch data of carangids Caranx sexfasciatus and
Caranx tille. The selectivity and residual curves were generated using four different individual
uni-normal (normal scale, normal location, gamma and log-normal) and bi-normal functions
with four different mesh sizes. Selectivity parameters were estimated using the SELECT (Share
Each LEngth Class Total) model which has been implemented in the software called GILLNET
(Generalized Including Log-Linear N Estimation Technique). Model deviance, Dispersion
parameter and Residual plots were used to determine the best fit of the data. The results
demonstrated that bi-normal model and uni-normal log-normal yielded good fit for C.
Sexfasciatus and C. tille respectively. Mesh sizes 14 and 14.5 cm performed better than the
modeled in both the catch data. Modal length increased with mesh sizes. Bi-normal model
yielded narrow selection range while log-normal model was of wider range. Shape and size
of the selectivity curves were identical and uniform in size. Over dispersion was common
in all selectivity models which in turn showed lack of fit irrespective of the models
Description
Keywords
Gillnet, selectivity, SELECT, fishing power, carangids
Citation
Fishery Techn 47(2):111-120