Mangaluru: A trawl boat owner from Mangaluru is working on mud crab cultivation using a recirculating aquaculture system (RAS). Bharath Kumar D, who launched the unit ‘Crab Shack’ on a pilot basis in Kulai, has set up a vertical farming system using nearly 200 stackable crates. The RAS method, equipped with automated filtration, allows for year-round production while efficiently utilising space, marking a significant shift from dependence on seasonal marine catch, he said. What began as a hobby has now evolved into a scalable venture. “It has been close to a year since I started crab cultivation at Kulai after a lot of trial and error. Since I own boats and know fishermen, I initially sourced crab seeds from them, and now we also have local vendors. I will soon hold discussions with officials of the Fisheries dept and the experts from the College of Fisheries on how to take this pilot further,” Bharath told TOI. Mud crabs, large edible crustaceans commonly found in tropical mangroves and estuaries, are known for their sweet meat. The species Scylla serrata is the most widely cultivated, with crabs capable of growing from 2.5-4 kg and often sold live in premium markets, he said. Bharath explained that the idea took shape during the last monsoon. “I went to catch crabs and then felt I should research more on how to grow them. I even considered visiting Singapore to study crab farming. Along with my friends Tejas and Nikshith, the trio now balances the venture alongside running a hotel and grocery store. The RAS setup ensures better water quality control and reduces reliance on natural tidal cycles. Sea water is transported to the facility twice a month using tankers, and the crabs are grown in 26-litre boxes,” he said. Starting with just 40 crates, Bharath gradually scaled up to 200, demonstrating the model’s viability. Crabs are ready for harvest in about 25-60 days. At the Kulai unit, the largest crab weighed 2.2 kg, reflecting favourable growth conditions under controlled environment. RAS-based mud crab farming is already popular in countries like Singapore, Malaysia and Vietnam, and is now gaining traction in Kerala, Tamil Nadu and Maharashtra. Bharath also conducts training workshops on advanced RAS and water filtration techniques. “At a time when the fishing industry is going through several challenges, such innovations are emerging as viable strategies, offering both economic stability and sustainable seafood production,” he added.
