The global seaweed industry has grown rapidly over the last two decades, and its connection with both livelihoods and environmental impacts have made it a candidate for a global sustainability certification scheme. To increase the efficacy of such schemes, we must understand their local contexts before they are implemented. This study investigates the localised power dynamics and perspectives within a carrageenan seaweed value chain in the Philippines, to identify implications for the development, implementation and uptake of a global seaweed NSMD certification scheme at this local level. Through 29 interviews with local value chain actors, large imbalances in local power were identified. Farmers appear to be the most vulnerable actors in this chain, and yet might be burdened with the costs and responsibility of compliance to a future certification scheme. This raises important considerations, and it may be that certification is not a suitable governance mechanism given current power dynamics.