Impact of the Invasive Fish Oreochromis mossambicus on Major Carp Culture in Jayakwadi Dam, Maharashtra

The introduction and subsequent establishment of invasive fish species pose significant ecological and economic challenges to inland fisheries worldwide. Among these, the Mozambique tilapia (Oreochromis mossambicus), originally introduced for aquaculture and fisheries enhancement, has become highly invasive in many tropical and subtropical freshwater systems. In India, reservoirs supporting Indian major carp (IMC) fisheries-Catla catla, Labeo rohita, and Cirrhinus mrigala-are increasingly experiencing ecological pressures from tilapia proliferation. The present paper synthesizes available literature on the biology and invasion ecology of O. mossambicus and evaluates its potential and documented impacts on major carp culture with special reference to Jayakwadi Dam, a large multipurpose reservoir in Maharashtra. Evidence from Indian and global reservoir studies is critically reviewed, and a tabulated synthesis of observed effects on carp recruitment, growth, and fishery yields is presented. The study highlights mechanisms of competition, habitat modification, altered fishery dynamics, and disease interactions. Finally, reservoir-specific management strategies and a framework for focused field investigation are proposed to support sustainable carp culture in systems where tilapia is already established.