The Rio Formoso estuarine system is located in the northeastern Brazilian coast in the state of Pernambuco, Brazil. The region is part of a costal and marine Guadalupe MPA, where conflicts between development, traditional use, human growth and habitat conservation have to be conciliated. Tourism development projects, intense fishing and shrimp farming are some of the uses already in place. One of the most traditional and common fishing techniques is the camboa fishery, with large nets, sustained by mangrove branches placed during low tide along river margins. From January to December 2000, catches of some camboas were registered monthly. Total catches varied in the period from 1 to 160 kg of fish. During the period, 45 goliath groupers were captured, ranging in size from 11 to 40 cm TL. Anecdotal reports from fishers in the Rio Formoso area indicate that much larger individuals were commonly observed in the past. In 2002 the goliath grouper was protected by federal law, but juveniles are probably still captured in estuarine areas. In July 2007 a new survey has started in the area. Nets are family owned and the same 20 camboas are still in operation. A participatory tag and release program is proposed to study the movement and survival in the estuary and adjacent coral reefs. The discussion on the needs for the conservation of the species and its habitats is here proposed as part of a framework for co-management.