Indigenous Re-circulatory Aquaculture System (RAS) to enable marine finfish broodstock maturation developed by the Visakhapatnam Regional Centre of ICAR-Central Marine Fisheries Research Institute (CMFRI) will be dedicated to the nation here on Tuesday by Dr. Trilochan Mohapatra, secretary, Department of Agriculture Research Education (DARE), Ministry of Agriculture and Farmers Welfare.
Dr. Mohapatra, who is the Director General of Indian Council of Agricultural Research, will be on a brief visit to the city. He will visit CMFRI facility here and dedicate RAS to the nation.
Various components of RAS are connected to a broodstock tank and include rapid sand filter (RSF) to remove suspended solids, protein skimmer to eliminate dissolved solids and biological filter to reduce biochemical waste.
Broodstock tanks built at CMFRI campus are of 125 metres capacity with eight m diameter and 2.5 m depth as the volume is considered ideal for effective management. The tank area is covered with galvanised iron (GI) roofing and sides remained open to allow entry of natural light.
The cost of RAS components (excluding broodstock tank) is ₹4 lakh and the daily power consumption is 36 kilowatts.
The whole tank water gets re-circulated 300% per day and the water is added at the rate of 3% to top-up the loss caused due to protein skimmer and backwashes of rapid sand filter.
The RAS is designed to reduce ammonia nitrogen by 87.3% and nitrite nitrogen by 81.7%.
Senior scientist in-charge of CMFRI-Vizag Shubadeep Ghosh told The Hindu that they had already developed broodstock for Pompano and grouper to facilitate large-scale commercial production.
RAS is gaining importance to maximise fish growth, flexibility to have production facilities near large markets, ease of harvesting and quick and effective disease control.
Dr. Ghosh said efforts were on to increase to achieve the entire production cycle of commercially important fish in RAS to overcome the difficulties in getting live broodstock from the wild, high cost, bio-security problems and impact on the marine ecosystem.
“The RAS is working excellently for maturation of marine finfish broodstock and for repetitive natural spawning without water exchange for the last one year suggesting its role in maintaining optimum water quality required for year round maturation and natural breeding,” Dr. Ghosh said.
