Browsing by Author "Minagawa, Megumi"
Diet and harvesting regimen for the production of mud crab Scylla olivacea in brackish water ponds EM Rodriguez, AT Triño & M Minagawa -
Fisheries Science, 2003 - Japanese Society of Fisheries ScienceThe effects of diet (fish bycatch or a mixed diet of 75% brown mussel flesh and 25% cooked cracked corn) and harvesting regimen (bimonthly selective harvesting, or single terminal harvesting) on growth, survival and production of mud crab Scylla olivacea (Herbst) in brackish water ponds were determined in a replicated factorial experiment. The crabs were stocked at 0.6 individuals per m2 for 118 days. There was no significant interaction (P > 0.05) between the diet and harvesting regimen treatments. Regardless of diet, the survival rate and net production of mud crabs were significantly higher (P < 0.05) when crabs were subjected to bimonthly selective harvesting than at single terminal harvest. Comparative cost–return analysis showed that bimonthly selective harvesting and mixed diet treatments attained higher net return and return on investment, and lower cost of production than the other treatments. Partial budgeting analysis showed that bigger profits can be earned by using a bimonthly selective harvesting and a mixed diet of 75% fresh or fresh-frozen brown mussel flesh and 25% cooked cracked corn.
Conference paperM Minagawa - In JH Primavera, LMB Garcia, MT Castaños & MB Surtida (Eds.), Mangrove-Friendly Aquaculture : Proceedings of the Workshop on Mangrove-Friendly Aquaculture organized by the SEAFDEC Aquaculture Department, January 11-15, 1999, Iloilo City, Philippines, 2000 - Southeast Asian Fisheries Development Center, Aquaculture DepartmentAlthough Japan has large-scale aquaculture, there is no aquaculture development in mangrove areas because the total area is small (553 ha) and strictly protected. Mangroves are preserved in comparatively good condition. Future development of aquaculture in mangrove areas is considered small-scale. Rather than aquaculture, Japan practices enhancement and management of wild fisheries. Tourism is another industry that would have an important role in mangrove utilization. But basic research on mangrove ecosystems is essential prior to determining policies for utilization of mangrove areas. International cooperative research work is important to encourage mangrove-friendly aquaculture and protect the environment.