A Living Seawall

Coquina boulders are the base of the living seawall.

Quick Facts

Amenities

4 listed

Bicycle - Rack, Historical/Interpretive Information/Exhibits, Scenic View/Photo Spot, Wheelchair Accessible

Over the years, the historic seawall bordering the southern grounds of the Castillo de San Marcos has been weakened by hurricanes, high tides, and the simple crashing of waves. Concurrently, rainwater percolating down through the mowed grounds has undermined the wall as the water seeps out into the bay. These forces have helped destabilize the historic seawall and make its long-term future uncertain.

In 2011 the National Park Service facilitated the construction of a living seawall 25 feet eastward of the original seawall. The living seawall is constructed of coquina boulders. (Coquina is the same stone from which the Castillo is built, which has stood strong for more than three centuries.) Over time, sand and sediment will wash through gaps in the new seawall and build up between the two walls, which will help stabilize the historic seawall. This new substrate will also create a habitat for oysters, marsh grass, and black mangroves, which will in turn attract marine life such as crabs, shrimp, and fish. At the same time, the coquina boulders and the oysters that adhere to them will act as a breakwater, reflecting pummeling wave energy away from the vulnerable historic seawall. It is hoped that the creation of natural habitat will help preserve a historic resource for many years to come.