Mesh and Hook Selectivity of Larger Carangid Caranx ignobilis (Forsskal, 1775), Captured along the Kanyakumari Coast of India

• Published in: Journal of coastal research 2024-04, Vol.40 (3), p.554-562
• Main Authors: Balasubramanian, A., Meenakumari, B., Pravin, P., Boopendranath, M.R., Rajani, M., Erzini, K.
• Format: Article
• Language: English
• Subjects: binormal; Caranx ignobilis; Dispersion; Finite element method; Fish; Fisheries; Fishers; Fishery data; Fishing; Fishing lines; Fishing nets; Gillnet; Gillnets; Hand line; Hooks; Mathematical models; modal length; Parameter estimation; SELECT; Statistical analysis; uninormal
• ISSN: 0749-0208; 1551-5036
• DOI: 10.2112/JCOASTRES-D-23-00051.1

Balasubramanian, A.; Meenakumari, B.; Pravin, P.; Boopendranath, M.R.; Rajani, M., and Erzini, K., 2024. Mesh and hook selectivity of larger carangid Caranx ignobilis (Forsskal, 1775), captured along the Kanyakumari coast of India. Journal of Coastal Research, 40(3), 554–562. Charlotte (North Carolina), ISSN 0749-0208. The larger carangid Caranx ignobilis is one of the key commercial fisheries operated by traditional fishermen on the Kanyakumari coast of Tamil Nadu, India, using larger meshed gillnet and drift hand lines. No selectivity study was conducted for this species in chosen study area; selectivity studies were conducted for C. ignobilis using different larger meshed gillnets having mesh sizes of 13.5, 14.0, 14.5 and 15.0 cm and hooks No. 5,6,7, and 8. Catch data obtained from gillnets and hooks were appropriated into various uninormal models (i.e. normal scale, normal location, log-normal, and gamma model) and a binormal model for finding the best fit that employs the share each length catch total (SELECT) methodology incorporated in Generalised Including Log-Linear N Estimation Technique (GILLNET) software. The estimated parameters of these models were evaluated using the statistical tools (i.e. model deviance, dispersion parameter, residual plots) to determine the best fit of the selectivity data. The binormal model under equal fishing power and fishing power proportional to hook size were found as best fit for the gillnet and hook selection data respectively. For all meshes and hooks tested, mesh size of 14.5 cm and hook No. 5 showed good catching efficiency capturing the respective modal length of fish 63.3 cm and 62.4 cm, which revealed that modal length of fish caught in the experimental mesh size is greater than the gears used by the traditional fishermen. Gillnet catch data appropriately converged into unimode in the selection curve, whereas the hook catch data appeared with bimode under the binormal model. Over dispersion was common phenomena in catch data obtained from gillnet and hooks because of the dispersed nature of population and the abundance of a larger size of fish in the study area.