The Tungabhadra Reservoir Unit (RU) oversees the fisheries activities in the Tungabhadra reservoir.Bio-mass of the reservoir is increased by seeding of the reservoir through pen culture. In order to rear the required number of fish seeds by culture of major carp spawn, pen culture is being practiced in the Tungabhadra Reservoir since 1982-83 in the pens located on the periphery of the reservoir. It is the first reservoir in the country to experiment with and perfect this technique. About 7.6 million fingerlings are stocked in the reservoir. In addition to the pen culture practiced in the reservoir to increase its bio-mass, the reservoir is directly being stocked with unsold fingerlings remaining in the fish farm. Fishery rights of Tungabhadra Reservoir are auctioned by Tender-cum-Auction System.
Interested parties can contact Fisheries Development Officer of the Board.
Fish pens are single layered enclosures of mono-filament cloth. They are very simple in design. Materials required for construction of pens are casuarina poles, bamboos, mono-filament cloth, coir rope and nylon twine. While construction of 10m x 10m x 1m cement nursery pond costs about Rs.40,000/- and earthen nursery of same size costs about Rs.8,000/- the 3 pen chamber of same size cost about Rs.500/- only. Further, the materials used in erection of a pen can be reused for about 4 years with replacement cost of about 10% of the original cost, every year.
For a water spread area of 37,814 ha with an optimum population density of 200 fingerlings per ha about 7.6 million fingerlings are required for stocking the reservoir. For pen culture the area of water body shall be 3 to 6 feet deep and should be so located that the winds and wave action is minimum. Suitable areas away from the main current in the reservoir are available near Ladakanabhavi village, Kasanakandi village and Hampasagara village. The site near Ladakanabhavi village has been used for pen culture during the period 1986-87 to 1996-97. The area is slopy and water slowly enters the pens when the reservoir water level is at 495.91m (1627 ft.). When the reservoir is full at 497.75m (1633 ft.) about 1.83m (6 ft) water depth is available for rearing of spawn. Due to continuous use of manure the fertility of the land and consequently the algal growth in the area has increased making the site unsuitable for use. So starting from 1997-98 season a new site at Baganal village has been used for the purpose. The pen area which was 1.23 acres (0.49 ha) during1982-83 was expanded to 8.25 acres (3.30 ha) during 1989-90.Although pen area has not been increased subsequently the stocking density of spawn in pens has been increased to optimal level.