Driven by concerns about food safety and illegal fishing, major seafood companies are working to improve how they trace fish through the industry’s complex supply chains. But in many parts of the world, fish are caught by artisanal fishers, not by massive trawlers. For these small-scale fishers, existing tracing technologies are often too cumbersome, complex, or expensive to use. This means they are often ineligible for sustainability certification (and the economic benefits that entails), because they can’t prove where, when, and how their fish were taken.