POPULATION DYNAMIC AND EXPLOITATION RATE OF THE BLUE SWIMMING CRAB (Portunus pelagicus) IN THE KENDARI BAY WATERS

Abstract

Kendari Bay waters consitute a potential blue swimming crab (BSC) fishing ground in WPP NRI 714 (the Banda Sea). The intensive fishing activities have been increasing from year to year that raised concern to the fishing that will disturb resource sustainability. Therefore, an alternative sustainable management is advisable. The purpose of this research was to examine the population dynamics and exploitation rate of BSC in the Kendari Bay waters conducted between January and November 2016. The results show the isometric of BSC growth pattern and balance of male and female ratio. The length at first capture (L c ) of BSC was 116.65 mm (carapace width),smaller than the length at first maturity (L m ) at 119.7 mm (carapace width). The von Bertalanffy growth equation for the blue swimming crab was L(t) = 182.0[1-e -0.91 (t - 0) ] and the fishing mortality rate (F) was higher than the natural mortality rate (M). The blue swimming crab exploitation rate calculated BSC from Kendari Bay has exceeded the optimum rate of 0.73 per year and is indicating a category “overfishing”. Therefore, to maintain the BSC stock sustainability, a management measure is needed to reduce the current fishing effort of approximately 46 % from the current effort and regulation of net mesh size.