BREVARD COUNTY, Fla. – For more than a decade, Restore Our Shores has been working to restore oyster reefs in the Indian River Lagoon, a vital estuary along Florida’s east coast.
The organization’s efforts have helped bring back these keystone species, which play a crucial role in water quality, habitat creation, and shoreline protection.
At one spot just north of Turkey Creek, researchers have been monitoring oyster health for nearly three years.
“You can really see the oysters and the diversity of creatures living along the reef just from visuals above the water,” said Hope Leonard, conservation restoration coordinator with Brevard Zoo’s Restore Our Shores program.
Leonard and a team of researchers and volunteers worked from a pier in Palm Bay. The reef, just feet from shore, is one of the most successful oyster restoration projects in the lagoon.
“Would you mind grabbing the spat apparatus for me,” Leonard called down to her colleague in the water. “Drag it over here and I’ll hand you the scissors from up here.”
The team is retrieving samples placed in the river last month.
Leonard calls oysters a “quadruple threat” in restoration efforts. They filter algae from the water, create habitat by growing in dense reef structures, prevent erosion, and remove excess nutrients that fuel harmful algae blooms.
These blooms, caused by nutrient pollution from sewage spills, septic leakage, and farm runoff, can block sunlight to seagrass and lead to fish kills when algae die and decompose.
To better understand oyster reproduction and health, researchers place clean oyster shells in the water monthly to attract oyster larvae, called spat.
“So, we don’t put any live oysters in the water for this project. We actually are just putting blank recycled oyster shell in the water for spat to find, and then we take it out, we’ll bring it back to the lab, we’ll take a look at the spat under a big magnifying glass, count it and see how the larvae populations are shifting throughout the year.”
These spat settle on the shells and grow into new oysters.
“Last April, we found over 2,000 oyster spat on a single shell, which is very promising,” Leonard said.
But Leonard says they’re still seeing a lack of consistent spawning from oysters in other parts of the river. It’s not fully understood whether oyster reproduction has been limited by local environmental factors or disease.
The study compares restored reefs, natural reefs farther south, and oysters grown by volunteers in Brevard County through an oyster gardening program that produced over 140,000 oysters last year.
Understanding more about the challenges that this species faces here in Brevard will help ROS and other restoration organizations make informed decisions on future oyster restoration projects.
“We want to see the oyster health in the Indian River Lagoon because we’ve been restoring them for over 15 years now. And without taking a look at some of the limiting factors, we can’t necessarily change and alter for the future.”
Researchers also collect live oysters to analyze their blood, reproductive cells, and overall health, looking for diseases and parasites that could affect restoration success.
Oyster reefs once covered much of the Indian River Lagoon, providing essential habitat for species like blue crabs, stone crabs, and mangrove snapper.
Overharvesting and declining water quality have drastically reduced oyster populations and reef structures. “Boat wakes and increased water energy have diminished the little oyster reef left,” Leonard explained.
Despite these challenges, restoration efforts have seen success. “We’ve built over 100 oyster reef projects in the lagoon,” Leonard said. “We’re hoping to increase the surface area for oyster larvae to settle and boost filtration power in the lagoon.”
Oysters can filter 20 to 30 gallons of water daily in natural settings, removing algae and converting inorganic nitrogen into forms that bacteria can process and release as nitrogen gas. This natural nitrogen cycle helps reduce nutrient pollution.
“That’s roughly, the equivalent of us drinking a cement truck in a day and filtering the water, if you compare body mass to the amount,” Leonard said. “It’s insane, it’s just incredible.”
“We’ve seen as high as 1,000 oysters per square meter. A square meter is probably four by four feet. That’s an insane amount of filtration power.”
The community’s commitment to restoration is strong. Brevard County residents passed the Save Our Indian River Lagoon sales tax, which funds oyster reef building, oyster and clam gardening programs, and seagrass nursery operations.
Leonard, who grew up in Brevard County, finds personal meaning in the work. “I’ve seen the lagoon decline since I was young, and it’s rewarding to see positive changes from our restoration efforts,” she said. “It’s inspiring to think about the future and the next generation of conservationists.”
The oyster health study will continue for another year, providing valuable data to improve restoration strategies and ensure sustainable oyster populations in the Indian River Lagoon.
“I feel like some of the blood, sweat and tears that we’ve put in and some of these things that we have stood for over the last few years with our oyster reef and with improving our oyster Reef. It makes it. Feel very worth it. It’s very rewarding.”