Population Parameters and Exploitation Ratio of Blue Swimming Crab, Portunus pelagicus (Linnaeus, 1758) from the Bawasalo Waters Pangkep Regency, South Sulawesi

A total of 1315 individuals were collected from the catches off the Bawasalo waters during  March -August 2023. This study aimed to analyze the population parameters and exploitation rate of blue swimming crab (Portunus pelagicus), caught by fishermen using a bubu naga fishing gear in the waters of Bawasalo, Pangkep District, South Sulawesi. The observed parameters included the size distribution of the carapace width, carapace width-weights relationship, age group, growth rate, total mortality rate, natural rate, fishing rate, and exploitation ratio analyzed with the ELEFAN II program. The size of carapace width ranged from 6.70 to 13.80cm, with the highest proportion observed at carapace widths between 9.10 and 9.60cm (19.7%) and the lowest proportion observed at carapace widths between 13.3 and 13.8cm (0.2%). Carapace widths below 10cm accounted for 66.69% of captures, while those above 10cm accounted for 33.31%. The carapace width-weight relationship was computed as W = 0.1038L^2.7334 (negative allometric). The von Bertalanffy growth parameters were estimated to be K = 0.41 yr^-1, Lmax = 15.10 cm, and t0 = -0.723 yr. The total mortality (Z), natural mortality (M), and fishing mortality (F) were calculated as 2.70, 1.22, and 1.48 yr^-1, respectively. The exploitation rate (E = 0.55) suggests that the stock of P. pelagicus was slightly higher than that of an optimally exploited stock.