This paper analyses the financial performances in terms of productivity and profitability indices and environmental sustainability with regards to Maximum Sustainable Yield (MSY) through the application of the Gordon-Schaefer Model for the coldwater Primary Fishermen Cooperative Society (PFCS). For this purpose, data has been collected from the secondary sources for the periods 2013-14 to 2018-19. The panel data analysis was carried out to derived the results using the method of ordinary least squares. The study found that PFCS such as Sribadam, Maneybong-Sopakha and Mangshilla have performed better in financial management but there is a probability of thread of sustainability in the future because in some of the periods their actual yield surpasses the MSY. On the other hand, PFCS like Rimbik, Chujachen and Dalep have not been able to bring their financial performances up to the mark because they were more concerned for sustainability. Excessive extraction of fishes from the water bodies for higher profit motive may lead to less availability for the coming generations. The study suggests that in aquaculture or fish farming, there should maintain an equilibrium between financial benefits and environmental sustainability and the resource should be utilised on a sustainable basis.