Freshwater in the Everglades and the Big Cypress Swamp drains south and southwest into coastal regions where it mixes with seawater to create the salinity gradients characteristic of productive estuarine and marine systems. Studies in Florida Bay have shown that over the last 100-200 years, salinity and seagrass distributions have fluctuated substantially in response to natural climatic cycles. The timing of this change coincides at least in part with the canal construction and landscape alterations in the Everglades that have altered the quantity, timing, distribution, and quality of surface water that flows south into the coastal waters. Federal and State agencies have undertaken a massive Everglades restoration project that will require changes in water management throughout the Everglades, and this will affect water flows to the coastal region. A major concern involves how changes in water flow could affect salinity and nutrient availability in coastal waters.