The shellfish solution: South Florida nonprofit builds oyster reefs and community to combat water pollution

Laura Elsenboss regularly spends her mornings laboring beneath the Florida sun, filling bags full of empty oyster shells — the leftovers of what once was a seafood dinner. In a few weeks, the bagged oysters will become the foundation of an oyster reef. 

“People always say to me, ‘Well that’s nice, you’re building oyster reefs. Why do we care?’” Elsenboss said. “And the ‘why’ is that oysters can filter up to 50 gallons of water a day.” 

Almost anyone who works with oysters — shelling them, farming them, bagging them, deploying them — will quickly inform you of that same fact. 

This fact quantifies the powerful filter-feeding capability of an oyster, a species which cleans the water it lives in by consuming suspended phytoplankton and algae. It encourages one to think of oysters as not just a high-end delicacy, but rather an unlikely variable in the fight against decades-old water quality concerns plaguing Stuart, Fla. — something the Florida Oceanographic Society has drilled into its lineup of local volunteers. 

The Florida Oceanographic Society, a small environmental nonprofit nestled on the island between the Indian River Lagoon and the Atlantic, has enlisted teams of volunteers to bag and deploy empty oyster shells into local waters since 2010. Using the remains of oyster appetizers, courtesy of local restaurants, the Florida Oceanographic Oyster Restoration program, or F.L.O.O.R., builds man-made oyster reefs across Stuart’s waterways, preventing erosion and reestablishing lost habitat.

Deployed oyster bags lay buried in the sand on the Indian River Lagoon’s shoreline. (Photo by Laila Mayfield)

“We are seeing great loss of oyster reefs in our area and worldwide,” said Sarah Cole, a research associate at FOS. “The freshwater pulses from Lake Okeechobee are a part of the reason oysters are so important, as well as part of the reason why we’ve lost so many oysters [in the area].” 

These “freshwater pulses” refer to the repeated water discharges from Lake Okeechobee pumped into Stuart through the St. Lucie River, which contaminates and kills the filter-feeding shellfish. But freshwater pulses aren’t the typical suspect of oyster loss. 

Worldwide, oyster populations have been decimated by an estimated 85%. In addition to overfishing and habitat degradation, South Florida’s oyster decline is partly a result of a statewide environmental crisis traced back to Florida’s largest body of water, Lake Okeechobee. 

In the early 1910s, the desire for farmland protection prompted a reorganization of water flow from the second largest lake in the U.S. The massive 143-mile, 2-story-high Herbert Hoover Dike now cradles Lake Okeechobee in a cement crib. The century-old decision cultivated one of the most profitable sugarcane-farming regions in the world, but not without diverting natural runoff to South Florida communities like Stuart.

Today, fertilizer-infused water from Lake Okeechobee seeps into the Indian River Lagoon, often regarded as one of the most diverse estuaries in the world, per the Florida State Parks organization. These periodic rainfall-induced dumps repeatedly result in blue-green algae blooms that stifle seagrass growth, stunt tourism and fishing, and threaten biodiversity. Oyster loss is just one example of destruction.

But while serious redistribution of water can only be instituted by the state of Florida at-large, the Florida Oceanographic Society has employed an interim solution to the oyster loss epidemic — one that requires the handiwork and heart of local residents. 

“We couldn’t do most of the things we do without our volunteers,” Cole said. “There’s only six scientists on our team, so a lot of the manpower is actually from volunteers.”

It’s loyal volunteers like husband-wife duo Laura Elsenboss and John Trahan that keep the program afloat. For the past seven years, the retirees have attended monthly oyster bagging events. The bags they fill are later deployed to local shorelines, where they serve as the substratum for oyster larvae called spat. Spat are attracted to hard surfaces where mature oysters are already present. The empty shells mimic a current reef, prompting oyster growth. 

“I like to call it good, dirty, fun work,” said Laura Elsenboss. “It’s very goal-oriented. It’s like, ‘OK! This table has gotta be completely bagged in two hours, let’s go!’ [John and I] work very well in that kind of situation.”

The couple continually praised FOS, crediting the organization’s coordination as part of the reason they’ve stayed so long and why others keep returning. Laura Elsenboss noted oyster shell bagging opportunities fill up almost immediately, with local citizens clinging to each spot as if it’s a reward, not a task.

With such intense engagement, it may come as a surprise that many FOS volunteers knew very little about oysters when beginning their service. 

But learning is part of the appeal. As a former molecular biologist who worked for 24 years at Pfizer Pharmaceuticals, Laura Elsenboss specifically sought volunteer work that would educate her about unfamiliar fields of science.

“Most of it has been learned on the job,” Laura Elsenboss said. “That’s the other thing I really like about FOS. They provide a lot of education and continual learning and growth.”

FOS volunteer and retired engineer Lisa Peery brought what she learned from FOS back home — literally. Under the guidance of FOS researchers, her waterfront abode on the St. Lucie river was converted into a shelter for three small oyster gardens in February. 

Cylindrical metal cages filled with empty oyster shells hang off of Peery’s wooden dock, attached by a retractable rope. Each week, Peery pulls the cage from the water like an anchor, gingerly rinsing off the structure with fresh water. She then leaves the cage arid in the shade for approximately two hours, a technique used to rid the garden of oyster-eating organisms like flatworms. 

In nine months, the oyster gardens will be returned to FOS as the foundation for a fully-fledged oyster reef, Peery said. 

FOS volunteer Lisa Peery inspects one of the oyster gardens that hang off of her dock on the St. Lucie River. (Photo by Laila Mayfield)

Peery remembers the first time she visited FOS just under three years ago as a new resident, thinking fondly of how exhibits were aligned with current environmental issues. 

“From the first visit, [FOS] tells you how to get involved, how to volunteer. They make it so easy,” Peery said.

One of those volunteers, 17-year-old Jake Hester, felt a mutual appreciation for environmental education, only this time as a student mentor. 

Hester works as an exhibit guide at FOS, where oyster education continues beyond the restoration program. At the coastal center, a table layered with empty oyster shells reminds FOS visitors of F.L.O.O.R.’s goals. Visitors are encouraged to fill mesh plastic bags with the salty, calcified oyster remains themselves — a task that not only educates, but employs. The bagged oysters from the exhibit are then used in actual oyster reefs. 

“Every time I would walk by [the exhibit], I’d see kids playing with the oyster shells while their parents read about the restoration project,” Hester said. 

Guests at FOS walk past the F.L.O.O.R. exhibit at the Florida Oceanographic Coastal Center in Stuart. (Photo by Laila Mayfield)

For the past 13 years, F.L.O.O.R. has planted 30 oyster reefs across Martin, St. Lucie and Brevard Counties. But the program has come to an untimely pause. The Florida Department of Environmental Protection and the U.S. Army Corps of Engineers have yet to issue permits that allow further establishment of oyster reefs. Until coastal water usage permits are provided, shells from restaurants pile up, unused and stressing FOS’ limited space. 

“If we could kind of get ahead of the curve, maybe we’d be better off. But we’re not getting to establish enough reefs to keep the water in good shape,” John Trahan said in regards to the issue. 

With the remains of 2022’s hurricane season brewing in Lake Okeechobee, an especially severe toxic algae dump has become imminent this summer, depending solely on Mother Nature’s penchant for precipitation. 

But no matter the level of destruction, Stuart’s local waterways are protected by a line of defense unlike any other — the local residents. 

“I think the most successful part [of FLOOR] is working with the community, getting people aware, getting them to care,” Cole said. “I think people just don’t know what oysters do. Teaching people the benefits of an oyster reef and why it’s important that we keep them around is the biggest benefit, so that in the future [the community will] go further and further to eventually restore it.”

Patches of oyster bags are laid off the St. Lucie River in Downtown Stuart, Fla. (Photo by Laila Mayfield)