Ocean governance is constituted by a range of institutions and actors across nation-states, markets, civil society and communities. As government-led management of commercial wild capture fisheries came under increased scrutiny following the rise of neo-liberalism and overfishing in the late 20th century, many non-governmental organizations and businesses turned to market and consumer-oriented approaches such as eco-labels and certification systems to define and reward sustainable fisheries and to incentivize change in others. However, our understanding of how small-scale fisheries in the Global South engage with these systems over time remains limited, particularly in the African context. This paper seeks to improve understanding by examining the interactions between diverse actors working to achieve Marine Stewardship Council certification for a small-scale fishery in The Gambia, West Africa, one of the earliest in Africa to engage the program. Situating the study within social science research on inequities and power imbalances in Southern engagements with Northern-led sustainability certifications, the case study analyzes qualitative data from documents and from 16 key-informant interviews. The data was organized using a social science approach which enables the analysis of factors promoting or hindering governance interactions and of who and what drives outcomes. Taking multiple factors into account, this paper argues that Southern interest in, and accessibility to, certification is dynamic, and influenced by the uneven distribution of regulatory resources, capacity, power and benefits. Promised but nebulous benefits clashed with arduous and recurring appraisals, exacerbating institutional factors leading the fishery to repeatedly fall short of certification. While important improvements can be gained from the pursuit of certification, Southern producers, managers and policy makers should have opportunities to be better informed about the diverse factors impacting: i) governance interactions and capacity building, ii) paths towards, and barriers to, improvements, and ii) the likelihood, or not, for achieving equitable access and social development benefits, especially for marginalized producers. The role and significance of sustainability certification in future ocean governance will be shaped fundamentally by such knowledge.