Reservoirs are constructed for irrigation, hydropower, drinking water supply and flood control. Fisheries are an important secondary and fish is a by-product. The scattered distribution, diverse management regime, lack of application of scientific knowledge, weak governance and policy support are creating hindrances in realising the full fish production potential of India’s reservoirs.
Reservoirs are multiple-use community assets having a large number of stakeholders. Fisheries come under State List of constitutional arrangement and is governed under the Karnataka State Fisheries Act. Fish, often referred to as rich food for poor people, provides essential nourishment, especially quality proteins, fats, vitamins and minerals.
Fish contributes to food security as an important accompan-iment to rice-based diets in Asia. The per capita requirement of fish, on par with global average, would be 13 kg vis-à-vis the current availability of around 6.8 kg. Reservoirs have a major role to play to bridge the gap betw-een supply and demand for fish.
Reservoirs are becoming an important source of animal protein and employment opportunities, particularly to poorer sections of the rural community. In India, based on surface area, the reservoirs are classified as small (less than 1,000 hectares), medium (1,000 5,000 ha) and large (more than 5,000 ha).
Karnataka has 82 reservoirs in all with a combined water spread area of 2.72 lakh hectares and is 8.4 per cent of the total reservoir area of the country. At the national level, the state ranks first in the number of large reservoirs and second with respect to small reservoirs.
In addition to reservoirs, the state has a very large number of irrigation tanks with a total water spread area of 2.99 hectares. The huge resource of reservoirs and tanks offer excellent opportunity for augmenting fish production in an eco-friendly way.
The fishery rights of most of the reservoirs are vested with the Department of Fisheries. Small reservoirs are disposed on lease to fishermen cooperative societies or by issuing licenses to individual fishers whereas large reservoirs mostly through issue of licenses. When licenses are issued, the fisher folk expect the Fisheries Department to stock the fingerlings.
This commitment is a difficult task for the department to fulfil. Under the licence system of governance, the fishers will be only interested in exploitation of the stock and lack drive for the development of fisheries.
Annual stocking
The Central Inland Fisheries Research Institute (CIFRI) has developed technology simple, eco-friendly and easy to adopt by the non-literate fishermen for scientific management of reservoirs. Following practices like stocking of fish seed and regulated fishing, production can be enhanced by 500 per cent to a high of 250 kg/ha/year from the present low of 50 kg/ha in small reservoirs and from the present 30 kg/ha to 150 kg/ha in large reservoirs.
The growth rate of native carps is slow, their stock is low and may attain around 0.5 kg in one year. The Gangetic carp registers faster growth, attaining one kg or higher, in one year. As they do not reproduce in most of peninsular reservoirs, annual stocking of their seed is essential to increase fish production. Commercially, fish seed that is available is mostly at fry stage (1 inch length) and stocking fry, the prevalent practice, results in high mortality.
Hence, stocking seed at fingerling size (around 4 inch) is necessary. Transport of fry to reservoir site from seed production farms and rearing them to fingerling stage by fishers themselves is cost effective. The fingerlings can be reared in ponds dug adjacent to shoreline or in cages floated within reservoirs and can be released to the same reservoir. The released fingerlings should be allowed to grow for about a year to reach table-size of 1 kg before harvesting.
The fishermen community is disorganised, lacks political support and leadership. Building st-rong leadership within the community and facilitating them to form cooperative societies is necessary. This will help counter multi-use conflicts, coordinate and implement fisheries management practices successfully.
Inadequate marketing channels, marketing infrastructure, post-harvest processing and value addition are other issues that are hindering development of reservoir fisheries. Through scientific management, it is possible to realise fish production of about 50,000 tonnes from res-ervoirs of Karnataka. The prod-uction can further be enhanced by growing fish in cages, as dem-onstrated by the Fisheries Department of Krishnarajasagar reservoir in Mandya district.
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