Application of Environmental Management on the Farming Practice of Mud Crab Scylla Serrata at Coastal Area of Ujung Alang, Cilacap, Indonesia: Efforts toward Sustainable Aquaculture

Abstract

One of the biota associated strongly to the presence of mangrove forests as their habitat is the mangrove crab, Scylla serrata. Mangrove crab farming done in coastal areas the village of Ujung Alang, Cilacap was aimed to enlargement of the size of the juvenile (60g/ind.) to the commercial size (200g /ind.). Mutilation was done to determine the effect of the removal of part of locomotors and molting process. The experiment included 10 crabs without mutilation as a control (C); 10 crabs by removing the 3 left walking legs (T1); 10 crabs by removing the 3 right walking legs (T2); and 10 crabs by removing the 3 pairs of walking legs (T3). Monosex farming was done using a box made of polyethylene as a shelter. Based on observations during the 8 weeks, T3 treatment gave the highest score in body weight and carapace width and length. The first molting (M1) occurred for the crab-treated T3 has the best percentage of molting (100%) compared to other treatments. The observation area of crab farming, the natural habitat of mangrove forests or in the control area found as many as 82 species of macrobenthos of 44 families and of the 4 classes that include gastropods (60 species), polychaetes (14 species), bivalves (6 species), and crustaceans (2 species). Based on biotic and abiotic factors, the area of aquaculture and mangrove areas did not show significant differences, indicating the farming practices Scylla serrata in the shelter system is environmentally save.