The barrier islands off the Alabama Gulf Coast are popular nesting spots for shorebirds and diamondback terrapins – both at-risk species thanks in large part to human activity.
The Nature Conservancy recently began a restoration project to rebuild Coffee Island, a barrier island located in the Mississippi Sound. Since the 1950s, dredging along the Gulf Coast has destroyed oyster reefs that helped protect the islands from storm surge and sea level rise. Those threats are now amplified by climate change.
“We were never able to go back and replenish those natural reefs,” said Mary Kate Brown, The Nature Conservancy’s Coastal Programs Director.
On Coffee Island, The Nature Conservancy is working to create a “living shoreline,” using natural materials like local grasses, sediment, and oyster shells to rebuild the coastal habitat. They are also installing 80,000 tons of limestone rock along a 2-mile stretch of the island to combat erosion. Engineers designed the breakwaters to be slightly above sea level.
“We don't want to make it too high that it's like a seawall,” Brown said. “So it's not a detriment to the whole ecosystem.”
But slightly higher elevation will help reduce the incoming wave energy on the shoreline by half.
“What we're trying to do is put down a stronger barrier to slow down the wave erosion and allow for that island to kind of rebuild its marshy shoreline,” Brown said.
Brown said the rocks will not only help to protect the vulnerable marsh vegetation, but create more habitat for other sea critters in the coastal ecosystem.
“They provide little ‘crab condominiums,’” Brown said. “They're also kind of a nursery for all of our recreational and commercial fisheries.”
The rocky breakwaters can also serve as a surface for oysters, mussels and barnacles to build on.
The Nature Conservancy aims to finish the project in March 2027. Once it is complete, they will do post-construction monitoring for a year with the University of South Alabama. If the restoration proves successful, Brown said they will continue to expand their efforts across Coffee Island.
“So that we still have an island 50 years from now.”
