Estimating the ecosystem attributes and ecological carrying capacity of commercially important fishes for sustainable development of fisheries in a tropical reservoir

Context Fish production from Gayatri Reservoir in India remains substantially below the estimated potential, highlighting a considerable gap with actual yield, underscoring need for fisheries management. Aims To bridge the gap, trophic model of the reservoir was constructed to assess ecosystem functioning and inform science-based fisheries management. Methods Ecopath model developed with 14 ecological groups using monthly data from April 2022 to March 2023 and was parametrised using monthly biological and fisheries data collected from seven stations. Ecological carrying capacity of economically important groups, Indian major carp (Labeo catla, L. rohita and Cirrhinus mrigala), prawns (Macrobrachium rosenbergii and M. malcolmsonii) and Nile tilapia (Oreochromis niloticus), was estimated. Key results Ecological stability indices, such as total primary productivity : total respiration (6.12) and total primary productivity : total biomass (28.42), indicated that the ecosystem is in developmental phase. Ecological carrying capacity of Indian major carp, prawns and Nile tilapia were estimated at 7.875 5.925 and 5.39 Mg km−2 respectively. Conclusion Fish seed stocking within ecosystem limits can enhance fish production and Ecopath framework effectively guides carrying capacity estimation and fisheries management. Implications This investigation will be useful for developing strategies to maintain ecosystem stability and to formulate fish seed stocking programs in a scientific manner to ensure sustainable fisheries.