Analysis of fishery and stock of the portunid crab, Charybdis feriata (Linnaeus, 1758) from Veraval waters, north-west coast of India

Abstract

Fishery and stock characteristics of the portunid cab Charybdis feriata from the waters off the north-west coast of India was studied based on commercial trawl landings at Veraval during 2009-2011. Growth parameters L∞, K and t0 were estimated as 171.5 mm, 0.97 yr-1 and -0.10 yr respectively. Mortality parameters Z, M and F were 3.97 yr-1, 1.49 yr-1 and 2.48 yr-1 respectively. The length at capture (L50) and length at maturity (LM50) were 95.4 mm and 87.3 mm, respectively which indicates that crabs enter into peak exploitation phase after attaining sexual maturity. The bio-economic stock assessment model showed that the species can be exploited at the present fishing level to maintain the economy of the fishery at maximum level (MEY) or the effort can be increased by 2.4 times to maximise the yield (MSY) depending upon the management objective. However, since the stock recruitment relationship is not defined, as a precautionary approach, the effort should not be increased more than 1.3 times the present level to conserve the spawning stock.