The northeastern Gulf of Mexico is a tide-dominated embayment known as the Apalachee Bay. Rivers draining Florida and southern Georgia deposit sediment at the coastline. The shoreline is nonetheless irregular and relatively sediment-starved, with grass beds common. Tidal range is approximately 1 m. Rising tides flood the marsh grasses to depths ranging from several inches to 18 inches, deepening the numerous, meandering, tidal creeks that intersect the shoreline. At high tide the upper reaches of these creeks attain widths of 100 feet or more in the marshes, although in their incised channels nearer the Gulf, creek widths change much less. Falling tides expose shallow tidal creek-beds, oyster bars and mud flats. An extensive program has been undertaken to measure, on a micro-scale, changes in accretion, subsidence and sedimentation at a number of sites in intertidal areas of the Apalachee Bay coast. At each site sediment erosion tables (SET) and cryogenic coring plots have been established, with measurements of subsidence and accretion collected semi-annually, or more frequently at some sites. Additionally, lead-210 cores have been collected for long-term sedimentation rate analysis in both intertidal and subtidal environments at each site. Results indicate that the marshes in general are healthy, accreting at a rate that approximately compensates for subsidence and sea-level rise (locally 2 mm/yr). Response to periodic storms is complex, and apparently depends on the duration of the storm event.