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• The ecological status of the Beledanga wetland was found to be immature in Ecopath. • Optimum stocking density of Grass carp was calculated using the ECOPATH model for macrophyte management in the wetland. • The huge biomass of Eichhornia is negatively impacting the ecosystem functioning and maturity of the Beledanga wetland. • Maximization of sustainable fish production for improving the livelihood of the wetland fisher and in achieving the SDGs. Wetlands are recognized as one of the most productive aquatic ecosystems. This high productivity supports its enormous biodiversity, aiding a scope for the small scale fisheries within it. Basically, these wetlands act as platforms for culture-based fisheries (CBF) i.e practice of stocking fish seeds and harvesting the grow out fishes at later. Often in tropical wetlands, the high nutrient load and high temperature enable the luxurious growth of macrophytes. Moreover, this macrophyte infestation is considered as a bottleneck for wetland managers. Facing a similar situation our studied Beledanga wetland is a macrophyte-infested wetland and the invasive Eichhornia crassipes is the most dominant macrophyte species. Owing to the macrophyte problem, Grass carp have been stocked in it as a biocontrol agent, as grass carp is a known biocontrol agent for the macrophyte infestation situation and simultaneously it will raise the fish production. To ensure maximum sustainable production from the wetland by harnessing with the available resources, it is necessary to acquire knowledge about the system's ecological status and its ecological networks. Thus, the Ecopath based mass-balanced model is one of the best suitable tools to know about the ecological organization of this Beledanga wetland. Considering the available data (observational and literature data), this study has constructed a mass-balanced Ecopath model with 14 functional groups including all fish groups, birds, plankton, benthos and detritus. It has been found that the zooplankton and benthos are the most utilized group and the birds are the keystone group in this wetland system. This wetland possesses a lower transfer efficiency as well as a low Finn's cycling index (0.224%). The system is found as an immature system with moderate ascendancy and system reserve (overhead). Moreover, concerning the ecologically sustainable production from this wetland more virtual mass-balanced models were developed (i) to evaluate the optimum grass carp stocking to manage the macrophyte population and (ii) to assess the impact of the Eichhornia on the system functioning. The results show that the system can harbour 1.5 times more grass carp biomass than the present without hampering sustainability. Concerning the impact of Eichhornia , it has been noticed that this macrophyte affects the maturity and transfer process of the system. Moreover, its huge biomass only accumulates more detritus in the ecosystem. [ABSTRACT FROM AUTHOR]