FRAGMENTATION OF THE LAND-WATER MARGIN WITHIN THE NORTHERN AND CENTRAL INDIAN-RIVER LAGOON WATERSHED

Salt marshes, mangrove swamps, estuarine shrubs, tidal flats and estua rine waters dominate the natural communities of the coastal zone compr ising approximately 35% of the northern and central Indian River Lagoo n watershed. Fragmentation of natural communities within the Indian Ri ver Lagoon ecosystem has compartmentalized ecological and physiographi c functions that once operated at a larger scale. Natural community an d land cover GIS databases were used to identify shoreline areas withi n the Indian River Lagoon ecosystem that, because of their context wit hin the landscape, have become highly fragmented. Estuarine natural co mmunities occupied about 700 km of the 1,700 km land-water margin. Alm ost 40% of these salt marsh and swamp communities existed in isolated areas, 10 to 12,000 ha in size. Large natural area fragments, with hig h natural community heterogeneity, contiguous with the estuary were id entified as areas for land acquisition. Maintaining the diversity of e cological and physiographical functions within the Indian River Lagoon ecosystem is imperative for it's long-term conservation. Land managem ent and planning agencies must incorporate both the content and contex t of natural area units within the Indian River Lagoon to properly con serve the integrity of the ecosystem.