Recirculatory Aquaculture System (RAS) is a technology where water is recycled and reused after mechanical and biological filtration and removal of suspended matter and metabolites. This method is used for high- density culture of various species of fish, utilizing minimum land area and water.
Advantage of RAS –
Extended durability of tanks and equipment. Reduced dependency on antibiotics and therapeutants hence, advantage of getting high quality fish. Reduction of direct operational costs associated with feed, predator control and parasites. Potentially eliminate release of parasites to recipient waters. Risk reduction due to climatic factors, disease and parasite impacts. RAS production can promote flexibility in terms of location for farming, proximity to market. Enable production of a broad range of species irrespective of temperature requirements. Feed management is considerably enhanced in RAS when feeding can be closely monitored for 24 hrs. Enable secure production of non-endemic species. Judicial use of water and land areas.
Disadvantage of RAS –
Constant uninterrupted power supply is required if electric power fails than backup of electricity is required. Capital cost of starting a recirculating aquaculture system is high as compared to ponds and raceways.
Species suitable for RAS- Baramundi/ Asian Seabass/Bhetki (Lates calcarifer) Pangasius (Pangasianodon hypophthalmus) Cobia (Rachycentron canadum) Tilapia (Oreochromis niloticus) Rainbow Trout (Oncorhynchus mykiss), especially in Hilly/cold water Region Pearl spot/Karimeen (Etroplus suratensis) .
Bigyan Mihir Rout, Co-Founder-Shyamalasubarna Agro.Pvt.Ltd., B.F.Sc, M-7978196834,8018107825, www.shyamalasubarna.com