The Nassau River-St. Johns River Marshes and Fort Clinch State Park Aquatic Preserves comprise both estuarine and marine waters of exceptional biological and aesthetic value to the state. These aquatic preserves are a unique Florida representative of the "Sea Islands" usually associated with southern Georgia. A chain of sandy barrier islands, occasional inlets, and a combination of sounds, rivers, and extensive coastal marshland characterize these. The preserve areas consist of vast salt marsh estuary with numerous interconnecting tidal creeks, and channels as well as minor uplands (tree islands). Fort Clinch State Park Aquatic Preserve was designated for the primary purpose of establishing a protective aesthetic buffer for the state park and historic Fort Clinch. This preserve surrounds the state park and is comprised largely of open waters associated with St. Mary's Inlet, the Amelia River, and a three mile extension into the Atlantic Ocean off Amelia Island. The western boundary borders an extensive salt marsh system along Tiger Island. The northern boundary extends to the intracoastal waterway channel between the states of Florida and Georgia.
For more information: http://www.dep.state.fl.us/coastal/sites/nassau/info.htm