The Science

Along the 100 miles of the Georgia coast exists nearly 30% of the salt marsh habitat for the U.S Atlantic Coast. Estuaries are a transition zone between the land and the open ocean that receives freshwater influence from the land, and tidal and saltwater influence from the ocean. These areas are semi-enclosed and include sounds, inlets, intertidal and subtidal creeks. Major vegetation types of the United States Atlantic coastal estuaries includes mangroves, submerged aquatic vegetation (seagrass), and cord grass dominated salt marsh. These salt marshes are under threat not only by human development but also sea level rise.

Tides along the Georgia coast have large fluctuations throughout the day. On most days, the Georgia coast experiences two tidal cycles (two high, two low) within a 24 hour period. The difference between high and low tide can be as much as 8 feet. This means that water moves quickly, or with high energy in and out of the system. High energy waters tend to stir up the sand and silt from the bottom, keeping them suspended rather than sinking, causing the waters to have a muddy, murky appearance (also known as turbidity). The suspended silt and sand do not allow light to penetrate while the constant movement of the water makes it difficult for submerged plants to grow. Therefore, to our knowledge seagrass cannot grow in the estuaries of Georgia.

The expansive salt marshes of Georgia are critical for transporting nutrients from the land into the ocean, and thus provide feeding opportunities. While the salt marshes also provide important nesting and foraging habitat for a variety of birds, mammals and reptiles, this site is dedicated to aquatic species.

Salt marshes are under threat not only by human development but also sea level rise. The 2007 Intergovernmental Panel on Climate Change (IPCC) predicted that under different scenarios of population growth, economic development and carbon emissions, the sea levels may rise at the lowest 0.4 meters and at the highest 2 meters by the year 2100.  This means that there is a potential to lose nearly 45% of the salt marsh along coastal Georgia over the next century.

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