Mangrove forests dominate the low-energy intertidal zones of river deltas, lagoons, estuaries, and coastal systems in the tropics, subtropics, and along some temperate coasts. This ecosystem cycles various organic materials, chemical elements, and important nutrients that it traps. Along with acting as a physical trap and providing attachment surfaces for various marine organisms, mangroves also provide protected nursery areas for fishes. Many important commercial and recreational marine fish species and invertebrates use the mangrove ecosystem for foraging, protection, spawning and as a nursery habitat. In the past fifteen years, Port Everglades area has undergone significant physical changes and is still a highly active site for commercial and recreational use. By studying the ontogenetic migration of reef fish in this area, it will show the importance of habitats essential for early life-history stages of reef fish populations. This project will expand current research on the trophic connectivity within the local mangrove communities to develop a better understanding of energy flow between the local mangrove and coral reef ecosystems. During this study three species of reef fish, Lutjanus griseus (gray snapper), Haemulon sciurus (bluestriped grunt), and Archosargus probatocephalus (sheepshead), will be collected from two mangrove sites adjacent to Port Everglades and one reef site located offshore of Port Everglades in Broward County. All species will be analyzed using stable isotopes from otoliths and muscle tissues to evaluate ontogenetic migrations, foraging, and occupation within the mangrove and reef sites. These analyses will help identify the utilization of mangrove habitat by reef fish populations and connectivity to local reef habitats.