1. Complex social-ecological interactions underpin many environmental problems. 2. Drawing on comprehensive social and ecological data from five coral reef fishing communities in Kenya; including interviews with fishers, underwater visual census data of reef ecosystem condition, and time-series landings data; researchers show that positive ecological conditions are associated with ‘social-ecological network closure’ – i.e., fully linked and thus closed network structures between social actors and ecological resources. 3. Results suggest that investments in building community capacity that focus on establishing communication, trust, and a shared understanding among direct resource competitors may improve ecological conditions in coral reef fisheries.