Collecting mangrove grass. (Photo: University of Calcuta)
Mangrove grass perfect ingredient for prawn feed: scientists
Friday, January 11, 2013, 23:40 (GMT + 9)
A team of scientists at Calcutta University has discovered that farmers could use a neglected species of mangrove grass in the Sundarbans to make a cheap, nutritious and environmentally friendly feed for freshwater prawns.
Abhijit Mitra, Calcutta University's marine biologist, and his partners scientists Sufia Zaman and Subhrabikas Bhattacharyya, devised an experiment to discover whether floral feed could serve as a proper feed source for freshwater prawns. He implemented the pilot project at Swarupnagar village of North 24 Parganas district.
According to Mitra, using the formulated feed from the salt marsh grass Porteresia coarctata, which grows naturally and plentifully in the Sundarbans, beings multiple benefits, such as improving the aquatic health of ponds and boosting the growth and protein level of the giant freshwater prawn species Macrobrachium rosenbergii. Other benefits are a higher body weight and a more intense red colour, both of which increase their appeal in the market, and that the prawns mature more quickly than their counterparts raised on typical commercial feed.
The feed made with mangrove grass also includes soybean dust, mustard oil cake, rice bran and wheat bran, PTI reports.
"If adopted by the people of Sundarbans, the technology can aid their livelihood. Presently they are buying an imported commercial feed which costs them INR 52 (USD 0.95) per kg but this new herbal feed will cost them only INR 28 (USD 0.51)," Mitra said.
Another option for farmers is to sell the feed itself to their colleagues.
"Our investigation also shows that prawn farming in the freshwater system of Indian Sundarbans is an economically feasible project and the return can be enhanced, if specially formulated herbal feed is provided to the culture species instead of the traditional one," said Mitra.
All of the ingredients produce less waste and thereby enhance water quality, making an eco-friendly feed.
As the pond water quality improves, it removes the need to clear mangroves for wastewater removal systems such as canals and ditches.
Each year, India produces an estimated more than 30,000 tonnes of the prawn.
By Natalia Real