We explore optimal harvest conditions for Nunatsiavut's Arctic charr, a data-deficient yet economically and culturally important fishery for Labrador Inuit. In the past, arbitrarily set quotas in the absence of data on science and climate shifts have led to sustainability concerns. The fishery, adhering to conservation principles, continues at low intensity today, so as to support local employment and maintain sociocultural values, despite its low economic viability. Using the only available data for Nain's commercial fishery, we estimate intrinsic growth, catchability, and carrying capacity, which we then use in a bioeconomic model to estimate maximum economic yield. Results indicate that foregone commercial harvests are 75%-93% below optimal, before accounting for subsistence harvest. Improved understanding of the conditions under which subsistence and commercial fishing coexist alongside more investments in data collection to address scientific uncertainty can help provide clearer management guidance to meet harvest needs of both sectors and allow for better policies and governance of the fishery.