In Kerala, there are 30 man-made reservoirs in addition to the 44 rivers, five major fresh water lakes and countless number of garden tanks as fresh water resources. Only very little information is available regarding the limnology of these reservoirs. Hence this study.

Peppara Reservoir (latitude 8 degrees 7' and 8 deg 53' North, longitude 76 deg 40' and 77 deg 17' East) constructed across the Karaman River in the Thiruvanathapuram District, Kerala, India was selected for the study. Four stations were selected in the reservoir for regular monthly collections of water, plankton, benthos, and sediment for a period of one year from February, 1991 to January, 1992. Samples were analysed following standard methods (Golterman et al., 1978; Jhingran et al., 1988 and Holme and Mc Intyre, 1971). Statistical analysis were done following Snedecor and Cochran (1967).

The existing literature on limnology of several Indian and foreign reservoirs has been reviewed by covering 350 references. Since the ecosystem processes in reservoirs exhibit wide variations depending on meteorological, morphometry, and hydro-edaphic features of the impoundments, an effort has been made to gauge the influence of these abiotic variables on the production dynamics of the Peppara Reservoir.

Data on various water quality parameters, primary productivity and nutrient status are presented and discussed in detail. An attempt has also been made pertaining to the ecology, spatio-temporal distribution and systematics of biotic compartments-phytoplankton, zooplankton, and benthos, to the extent possible. The correlations between plankton, benthos, and different hydrographical parameters have been examined and discussed. The various management strategies for the development of reservoir fisheries in the state have been discussed in detail. Present scenario of the reservoir fisheries in the state has been highlighted and the factors responsible for the slow rate of development were discussed.