Private enumeration of landings data and traceability is an emerging phenomena in developing world tuna fisheries. The general goal of these systems is to facilitate compliance with mandatory market requirements such as the European Unions Illegal, Unreported and Unregulated fisheries regulation, as well as support aspirations for voluntary requirements such as the Marine Stewardship Council. The long-term success of these systems appears to be dependent on their ability to complement and extend government data and information systems. Developing and maintaining the credibility of these voluntary private enumeration and traceability systems requires strong market incentives as well as strong state support and assurance. If this credibility can be maintained private fisheries information systems may provide a promising basis for innovative stock assessment and management approaches relevant for complex developing world fisheries such as tuna.