Perspective: Saving Sapelo Island's Legacy from Sinking

Isolated from the world, I wallow in marsh mud that smells of sulfur.

It was summer 2021 and I just stepped foot onto land inhabited by the largest, most intact Geechee community in the United States. At nearly 12 miles long and less than 4 miles wide, Sapelo Island has a size comparable to that of Manhattan, but its slave-descendant population is only 70 people and shrinking. Lately, the island has struggled to retain its youth who leave in search of higher education and job opportunities. Land theft and cultural erasure are other issues that impact the remaining saltwater Geechees at Sapelo Island and are depicted in the book, God, Dr. Buzzard, and the Bolito Man, by Cornelia Walker Bailey.

A wetland on Sapelo Island as viewed from the road. (Jess Turner)

Home to the saltwater Geechee peoples, the University of Georgia Marine Institute, and the Sapelo Island National Estuarine Research Reserve, Sapelo Island brings researchers from around the country, including myself, to its shores. My initial goal was to test a low-cost sensor that could potentially predict the flow of carbon through an entire ecosystem. But what I came to realize through my work is that carbon is leaving the surface of the marsh on a much grander scale than what I had initially expected. Although it is no surprise to researchers of coastal environments, wetlands and deltas along the coasts move sediment and carbon from upland ecosystems out to sea. This is the opposite of what happens in inland wetlands like riverine fens, where only minuscule amounts of carbon are lost through flowing surface waters.

Substantial carbon loss from wetland surface waters is usually a symptom of sediment erosion and can be caused by rising seas or poor management. It is typically a sign of disturbance.

Evidence shows wetlands with restored natural water regimes can start to accumulate sediment more quickly, or increase carbon stored in soils, roots, and plants. Restoration can ultimately slow the speed of carbon loss through aquatic pathways. Rebuilding sediment to its original height can also jump-start soil carbon storage. These facts led me to wonder why carbon loss is happening on such a large scale at Sapelo Island, and what is being done about it?

The Reynolds Mansion was designed and built from tabby, a mixture of lime, shells, and water, by Thomas Spalding, an architect, statesman, and plantation owner who purchased the south end of Sapelo Island in 1802. Now, it is one of two Georgia Department of Natural Resources sites providing overnight lodging on the island. (Jess Turner)

To answer that question, I looked into the island’s history. Starting in 1948, the marsh at Sapelo Island was drained and diked for dairy foraging. Not long after, the marsh was rendered useless for both animals and humans due to the toxic buildup of sulfate in soils, a natural nutrient that is essential for plant growth but only in much smaller quantities. Clearly, the natural ebb and flow of water on the marsh surface is crucial to the functioning of the ecosystem.

Substantial carbon loss from wetland surface wate