Abstract
Blue swimming crab (
Portunus pelagicus
) supports a valuable export fishery in Indonesia, currently estimated at over $400 million per year and employing over 250 thousand workers. High demand has led to the overexploitation of
P. pelagicus
in recent decades. However, accurately assessing stocks and harvest rates can be difficult. Variation in estimates of harvest sustainability among government, industry, and independent institutions highlights the need for comprehensive assessments. In this study, we examine the crab population in an artisanal nearshore fishery in Parepare Bay, South Sulawesi. We conducted a monthly analysis of the fishery for one year using two methods: (1) surveys of harvested crabs at a landing site and (2) collections of unharvested crabs from four sites in the bay using crab traps. From both methods, the average carapace width for male and female
P. pelagicus
was approximately 10 cm, and around half of the harvested crabs had not reached maturity. Estimates of spawning potential ratio for
P. pelagicus
in this fishery were 4%–9%, indicating overexploitation of the stock and impaired recruitment. As an additional aim, we examined the relative abundance of species in the crab community. We found that the bay is dominated by other species of swimming crab, namely
Charybdis anisodon
and
Thalamita crenata
. These other species may be predators of
P. pelagicus
, and high predation rates may further contribute to juvenile mortality in this stock. Achieving a sustainable harvest of
P. pelagicus
will likely require multiple actions such as enforcement of regulations, restocking of juveniles, and the restoration and protection of nearshore habitats.