Model based Assessment and Management of Fisheries in Reservoirs

Abstract

Fish production from inland fisheries in India largely caters to the needs of domestic consumption as against marine fisheries, which is primarily diverted to exports. An increase in the production of inland fish would bridge the gap between domestic supply and demand while meeting the nutritional requirements of the population. Culture-based fisheries in reservoirs is a successful aquaculture practice in vogue in many parts of the world and also in India for enhancement of fi sh production. Population dynamics of stocked fishes in the reservoirs can be studied using density dependent growth models which off er a sound framework for adopting management measures for production enhancement. Kanjirapuzha reservoir with a total area of 515 ha is a small reservoir located at Palakkad district of Kerala which is less productive compared to other small reservoirs. In order to suggest appropriate management measures for production enhancement, the growth performances of Catla and Mrigal stocked at Kanjirapuzha reservoir was evaluated using density dependent model. The growth of Catla was high in the reservoir compared to Mrigal. The competition coefficient of the stocked fishes ranged from 0.0059 to 0.0095 g raised to 1/3 hakg raised to -1 indicating positive effect of population density on growth. The biomass for catla was estimated using the cohort analysis and it varied from 11 kgha raised to -1 to 23.6 kgha raised to -1 for the different age groups.