The exploitations status of the orange mud crub (Scylla olivacea Herbst, 1796) in Aru Islands and adjacent waters, Maluku, Indonesia

The increasing exploitation and fishing of the orange mud crab (Scylla olivacea) are threats against the sustainability of the crab resources. Therefore, it is critical to carry out a scientific study that can serve as the basis of the fisheries management. This study was carried out from March to November 2019 several crab landing sites in Aru Islands (Dobo). It employed survey and monthly data collection methods, assisted by an enumerator. The results revealed that the capace width orange mud crab was of 110–185 mm in size where 135 mm was the dominant size and 137.8 mm was the capace width at first capture (CWc). Its growth rate (K) was 0.59 per year and its asymptotic capace width was 191.5 mm. The recruitment of the species occurred all year long, peaking in February at 18.53%. Its fishing mortality (F) was 0.74 per year, while its natural mortality (M) was 0.77 per year. The exploitation rate (E) of the orange mud crab was 0.49% (moderate state). To ensure the sustainability of the crab resource in Aru Islands, people should be advised to maintain the sustainability of the crab habitats, i.e. the mangrove forests, and not to capture the orange mud crabs below 120 mm in size.