Salt marshes along the Gulf Coast of Florida and Alabama are highly productive ecosystems. They provide critical nursery habitat for a diverse array of fish and shellfish, including commercially important species such as blue crabs, penaeid shrimp, and gray snapper. Other marsh residents are a major food source for commercially fished species. This study addresses the indirect and direct impacts of the Deepwater Horizon oil spill on the living communities of salt-marshes and adjacent, vegetated, subtidal habitats, and explores potential oil impacts on the spawning stocks of species that rely on marshes for nursery habitat. The project addresses a key goal of the BP/FIO Gulf Oil Spill Prevention, Response and Recovery Program: conducting baseline studies and impact assessments to provide the basis for long-term monitoring.