The bay and back again: Recycled oyster shells used in environmental restoration

Savannah Chastain
Americorp volunteer, Jacob Shields and Choctawhatchee Basin Alliance (CBA) employee, Rachel Gwin load bins of shucked oysters into a truck to be used in the oyster recycling program.

Don’t be surprised if you see a blue truck and a trailer backing up to your favorite seafood restaurants this summer and filling up with oyster shells. The truck belongs to the Choctawhatchee Basin Alliance (CBA) and is stopping by to pick up shucked oysters for their recycle program, Offer Your Shell To Enhance Restoration (O.Y.S.T.E.R.). The program partners with local seafood restaurants to collect shells for use in building new reefs in the Choctawhatchee Bay.

“We started the shell pick up program three years ago,” said CBA Program Specialist, Rachel Gwin. “It was actually my Americorp group that started it. We were all talking about how many oyster shells go to waste, and how they are just taking up room in land-fills.”

Gwin told The Log that in the beginning of the program, the group called local restaurants to see if they would be willing to participate, but now the program is so popular that restaurants have begun contacting them.  

“On our busy days we’ve been averaging 18 bins a day during the summer,” said Gwin. “We go twice a week during the winter, but during spring break and summer we do three days a week, collecting recycling bins full of oysters from 10 area restaurants.” Gwin added that each bin weighs 342 pounds when full, and every year an average of 1,100 cubic yards of recycled shell is collected for the recycling process.

“It’s pretty impressive; it’s actually a lot of oysters,” she said.

Once the shells have been collected, they undergo a three-part process before being placed in the bay.

“We take them back to the campus, and dry them out for at least six weeks — this kills bacteria,” said Gwin, explaining that bacteria is destroyed by the natural process of rain and sunlight. “After they have dried out and baked in the sun, we move them to our bagging area, and use mesh bags to make blocks. Once they are bagged they are ready to use, and we move them out to be placed in our reefs.”

The CBA receives funding to build the reefs from grants, businesses and private homeowners, and for each reef project they must gain a permit before building.

“The permit requires all of our reefs to be shallow water reefs, 10-15 feet within tide line,” said Gwin. “They must be in non-harvestable waters, and be tall enough to see in high tide.” 

Gwin told The Log that volunteers and workers have become creative with the building of the reefs, as the permit also requires a break in the reef so that marine animals can swim through. “We have started experimenting with crescent shapes, building one concave and the next convex,” she said.  

To date the CBA has constructed 13 oyster shell reefs, spanning the perimeter of the Choctawhatchee Bay from Niceville to Point Washington.

“The first main reason for building the reefs is that it helps with the natural habitat,” said Gwin, adding that the reefs provide a haven for small marine life such as hermit crabs, small fish, and new live oysters.

“The second main reason is for erosion control,” Gwin said noting that a majority of the private homeowners contract CBA reefs for just that reason. “It’s amazing how much sand comes in behind the reef. It really helps to regain some of the land that was lost,” she said.  

Gwin explained that the third reason for building oyster reefs is to enhance the water quality.

 “Once oysters settle on the reefs, they help filter the water. A single oyster can filter 50 gallons of water per day,” she said.

The CBA also conducts oyster monitoring, to keep track of how many oysters have accumulated on the reefs, and making it possible to evaluate the change in water quality.

To find out more about The Choctawhatchee Basin Alliance, or the O.Y.S.T.E.R Shell Recycling Program visit To see a Google Earth rendering of the locations of the oyster reefs visit,