For generations, fishermen have constructed, shared, and refined knowledge (Traditional Ecological Knowledge) from their perceptions of habitats and species. Following our earlier work in La Parguera, Southwest Puerto Rico, we argue that fishers have a wealth of information on coastal ecosystem ecology, fish behavior, temporal patterns and spatial distribution. Recent work shows that fishers in other areas of Puerto Rico developed schemas that serve as cognitive models associating fishes, groups of fishes and habitats. This article explores the fishers' mental schema of habitats and the habitat-species coupling using the specific example of mutton snapper or sama (Lutjanus analis). Traditional ecological knowledge can be an important component of information used in Ecosystem Based Management. Furthermore, TEK can provide unique knowledge and perspectives on local ecology and the health of fishery resources.