CORPUS CHRISTI, Texas — Researchers at the Harte Research Institute at Texas A&M Corpus Christi are working to restore oyster reefs in the Coastal Bend — and the shells from your seafood dinner may be helping rebuild them.
Dr. Jennifer Pollack, the endowed chair for coastal conservation and restoration at the institute, said oyster reef populations have declined dramatically over time.
"We've lost over 90% of oyster reefs compared to historic levels. And so there's a real need to preserve what we have and also to restore what's been lost. We've recycled over 3.5 million pounds of oyster shell, and we've recycled those shells back into the water to rebuild over 45 acres of oyster reef."
Researchers collect those shells through the "Sink Your Shucks" oyster shell recycling program, which partners with more than 21 restaurants, 6 oyster farms, and several seafood festivals across the Coastal Bend. Partner restaurants collect used shells in large bins, which are picked up by a dump truck and transported to a stockpile at the Port of Corpus Christi. The shells are left to sun bleach and clean for six months before they are ready to be used in restoration.
Once ready, volunteers bag the shells into mesh bags that are placed back into the water. Those bags form the foundation of a reef, giving tiny baby oysters a surface to attach to and grow. Large-scale restoration projects use barges to transport stockpiled shells to carefully selected sites in the bay.
Pollack said the reefs benefit everyone in the Coastal Bend — not just oyster lovers.
"An oyster can filter dozens and dozens of gallons of water over the course of a day. That means that all of the oysters across all of the reefs in the coastal bend are just making cleaner, clearer bay waters for us to fish in and swim in, and do all the things we like."
One of the most important things oysters remove from the water is excess nitrogen, which can run off from fertilizers into the bay during heavy rain. When nitrogen levels get too high, it can trigger harmful algal blooms that cause respiratory irritation and eye discomfort for people along the coast. Pollack said oysters help prevent those effects by filtering excess nutrients out of the water before they can cause problems.
The benefits extend beyond water quality. Oyster reefs also serve as natural storm barriers along the shoreline.
"We know that oyster reefs, if they're close to the shore in shallow water, they can reduce the wave height of waves coming in by up to 50%. So that is a huge benefit for all of our roads and our infrastructure and our houses, hotels, everything that we like that's located right along the shoreline to help protect it," Pollack said.
That 50% reduction in wave height translates to roughly 75% of wave energy being dissipated before it ever reaches the shoreline. Pollack described oyster reefs as natural, living breakwaters — structures that grow taller and wider as oysters attach to one another, unlike static concrete seawalls. This approach is part of a broader concept known as living shorelines, which combines natural elements like oyster reefs with other materials to protect coasts without relying solely on hard infrastructure.
Oyster reefs also support a wide range of marine life. Crabs, shrimp, juvenile fish, and other species live in the nooks and crannies of the reef structure, making oyster reefs biodiversity hotspots that support local fishing.
Pollack said the full portfolio of benefits oysters provide makes them especially valuable in the Coastal Bend, which draws tourists seeking fresh seafood and an active coastal lifestyle.
Graduate student McKenna Reinsch is researching biodegradable alternatives to the plastic mesh bags traditionally used in oyster restoration. While plastic bags have proven effective at holding shells in place long enough for oysters to establish — ideally lasting about two years — they release pollutants into the water and contribute to marine debris.
Reinsch is testing several alternatives, including a biopolymer bag made from recycled potato chips by a company in the Netherlands, a bag woven from basalt fiber spun from melted volcanic rock, and structures made from jute fabric mixed with calcium-based cement. She is also testing what the team calls "shell cakes" — small cement structures mixed with recycled oyster shells from the Sink Your Shucks program. The design was adapted from larger units developed by the Marine Discovery Center in Florida and scaled down to make them easier for volunteers to handle.
Reinsch showed me the creatures living on the shell cakes during a recent sampling session.
"What's really cool that I'm seeing today is that on those little shell cakes I'm seeing a lot of juvenile fish that typically we don't see in the shell bag so it's almost like they're acting as a nursery," Reinsch said.
She said she spotted baby toadfish, baby gobies, and an abundance of crabs and shrimp on the structures. Among the more unusual finds: the naked goby, a small fish that gets its name from its lack of scales, giving it smooth skin similar to humans.
Reinsch said community involvement is a key part of the restoration work. Volunteers help mix the concrete, incorporate the shells, and form the bags used in the field — giving them a direct, lasting connection to the reefs being built.
The oysters people eat may ultimately end up back in the Gulf, rebuilding the reefs one oyster at a time.
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