Population dynamics of mud crab, Scylla olivacea (Herbst, 1796) from the Sundarbans of Bangladesh

Abstract The Sundarbans mangrove regions are the home of the mud crab ( Scylla olivacea ) business, as forest areas are potential places for random crab harvesting, trading, and exporting overseas seafood markets. Since the mud crab was being captured on a large‐scale in the wild for various purposes, estimation of population parameters were immediately done in terms of body weight and length‐frequency data collected from different locations in the forest of southwestern Bangladesh to understand the status of the stock. Recruitment pattern, growth parameters, mortality rates, and exploitation levels ( E ) were estimated to understand the population dynamics of S. olivacea . Asymptotic carapace widths ( CW ∝ ) were 14.70 and 14.18 cm, and growth co‐efficients ( K ) were 0.47 and 0.50 year –1 for male and female S. olivacea , respectively. The fishing mortalities were 2.32 and 1.13 year –1 and natural mortalities were 1.39 and 1.46 year –1 for males and females, respectively. Year‐round recruitment of this species takes place in the wild with a peak between June and November. The E for S. olivacea was found to be 0.63 for the male and 0.44 for the female. In summery, the stock of S. olivacea is found to be overexploited in the Sundarbans of Bangladesh. Therefore, mud crab resources should be taken into consideration under suitable fisheries management policies to conserve this national treasure in this delta. It is supposed that the findings will draw the attention of the scientists in the fields of aquatic biology, ecology, and management of the Sundarbans in restoring the mud crab population.