GUWAHATI, April 11 - The Raha-based College of Fisheries has developed a method of unconventional aquaculture, which it claims better and faster growth of fishes, besides increasing the survival rate considerably.
A series of experiments were conducted by a team from the college headed by Pradyut Kumar Goswami on pilot basis in several beels of Assam and the results were �very much encouraging�.
�Carp seeds having an average length of 2.07 cm were raised in specifically designed bamboo cages with explicit stocking densities and by formulating proper nutritional strategies. The small fishes registered phenomenal growth up to 19 cm in 45 days. It has been observed that generally three to four months of time are required to achieve such growth in earthen rearing ponds. At the same time, more than 80 per cent survival rate was found in cage-reared fishes, whereas less than 50 per cent of survival rate was recorded from the earthen-rearing tank,� Goswami told The Assam Tribune.
The most important and significant feature of cage aquaculture is that even if the structures are completely submerged by the water, the fishes cannot escape from it.
�The non-conventional method of aquaculture is designed to hold the organism in captive and increase the biomass by minimizing losses through predation, disease, natural calamities and exclusion of competitors. It also facilitates total harvesting. Therefore, this is one of the suitable technologies for fish culture in the flood-prone areas,� Goswami added.
Millions of fish fry and fingerlings get killed in both the banks of Brahmaputra and Barak rivers, and their tributaries annually due to the lack of storage facilities.
Goswami said if cages are installed people will be able to stock the naturally collected fishes which are very much superior to the artificially produced fish seeds in hatcheries and grow faster than them.
Moreover, if bamboo cages are fixed strongly in the marginal areas of rivers (tributaries) depending on the velocity of the water current horizontally, it would be able to check river erosion as well.
Hatchery owners would also be able to replenish their brood stock time to time to avoid inbreeding depression of the fishes and produce quality fish seed in the state which is believed to be one of the major barriers of sustainable fish production in Assam, according to the findings of the experiment.