Understanding the influence of future sea-level rise (SLR) on coastal ecosystems is improved by examining response of coastlines during historic periods of SLR. We evaluated stability and movement of the estuarine intertidal zone along eastern Gulf of Mexico, known as the BBig Bend^of Florida. This relatively undeveloped, low-energy coast is dominated by broad expanses of tidal marsh, providing an opportunity to observe unobstructed response of a coastal ecosystem to SLR. Features from nineteenth century topographic surveys and late twentieth century satellite imagery were compared. Relative change was calculated for intertidal area and lateral migration over 120 years, a period when tidal amplitude increased in addition to SLR. Loss of tidal marsh at the shoreline was −43 km 2 , representing a 9 % loss to open water. At the same time, 82 km 2 of forest converted to marsh and 66 km 2 of forest converted to forest-to-marsh transitional habitat. The result was a net regional gain of 105 km 2 of intertidal area, an increase of 23 %, constituting a marine transgression of coastal lowlands. Forest retreat was lower at zones of high freshwater input, attributable to salinity moderation and was further complicated by coastal morphology and land-use practices. Shoreline migration may not represent full extent of habitat change resulting from SLR in regions with low coastal gradients. Forest retreat was consistent with what would be predicted by an inundation model; however, shoreline loss was considerably less, resulting in a net increase in intertidal area in this sediment-limited coast.

SEA-LEVEL RISE AND MANGROVES Zuleika Pinion Responses of mangroves to sea-level rise Predictions and recent data Past analogues Accretion rate Management strategies 71 Community ecology and physiological ecology of mangroves: potential predictors of response to global change Mangrove forest zonation Mangrove response to freezing Hurricane damage Salinity, flooding, and sedimentation Conclusions References APPENDICES Appendix 1. Geographic distribution of coastal forest trees and shrubs on the Gulf of Mexico Appendix 2. Bibliography of tree species' responses to flooding and salinity Appendix 3. Field studies of responses of Gulf coast tree species to impoundments, drainage, and reductions in freshwater supply.

No abstract

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS.For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit

No abstract