How one Tampa Bay group aims to restore oyster reefs by collecting your leftover shells from local restaurants

Oyster Biologist Rick Radigan joined Tampa Bay Watch in 2020 because he wanted to make a difference. Before that, Radigan monitored Florida’s oyster populations for nine years with the Florida Fish and Wildlife Research Institute.

“At the state, all we did was monitor oyster populations,” Radigan told CL. “And I wanted to do something to change what we saw. I decided to apply for this position [at Tampa Bay Watch] because I wanted to be able to make the bay a better place. Because this is where I spend all my time. I go out on the water; I enjoy the water; my family enjoys the water; we all enjoy it.”

How do oysters make Tampa Bay a better place? First off, oysters clean the water.

“They are one of the best filter-feeding organisms in the world,” says Radigan, anecdotally. “An adult oyster, while it’s submerged, can filter up to two gallons of water an hour. So an adult oyster, depending on size and health of course, can filter up to roughly 50 gallons of water a day. So if you do the math, there are places in Tampa Bay that can support up to 1000 oysters per square meter. So you’re talking 50,000 gallons of water being filtered every 24 hours within one square meter.”

Second, they provide a habitat for Tampa Bay’s fish and crabs. Although humans don’t eat Tampa Bay’s wild oysters (urban oysters collect industrial pollutants), blue crab and stone crab do. And several Tampa Bay sport fish species congregate around oyster reefs, like red drum, black drum, snook and sheepshead.

“People from all over the world come to fish in Tampa Bay waters,” says Radigan. “That’s why it’s important to have these oyster reefs around.”

Third, oyster reefs help stabilize the shoreline.

“So as wave action and tide action and wind action and wake action all have an effect on our shorelines, these oyster reefs help to not only stabilize the sediment but also mitigate that energy that approaches the shoreline so we don’t get that coastal erosion…” says Radigan.

Unfortunately, aerial images show that Tampa Bay’s oyster reef habitats declined by about 83% between 1938 and 2020, likely due to climate change.

Tampa Bay Watch started its Community Oyster Reef Enhancement Program in the early 2000s to help restore lost oyster habitat in Tampa Bay. The program attempts to restore oyster reefs in Tampa Bay by providing a hard substrate — bags of fossilized shells — for oyster larvae to attach to. Their new Shells to Shoreline project feeds into these efforts by providing additional shells to fill shell bags and string from docks.

Radigan launched Tampa Bay Watch’s Shells to Shoreline Program in February 2022 with a single restaurant: The Island Grille & Raw Bar in Tierra Verde.

“The first year we were funded by Neptune Flood Insurance,” says Radigan. “They gave us a decent little grant to get the program up and running as a pilot. Shortly thereafter, we received a grant from Duke Energy. That allowed us to expand a little more…That funded us through 2023. Then, in July 2023, we secured a grant through NOAA partnering with Restore America’s Estuaries.”

The NOAA grant, which amounts to $1.14 million, enabled Tampa Bay Watch to hire two additional full-time staff members — Oyster Shell Recycling Program Specialists Reagan Fennessy and Paige Paddock. In addition to staffing, the grant funds new restaurant additions for the next three years.

Since Feb. 2022, Shells to Shoreline added nine more restaurants: Oystercatchers, Crabby Bill’s St. Pete Beach and Indian Rocks Beach locations, The Helm: Provisions & Coastal Fare, Cocos North Beach, The Oyster Bar, The Tide Seafood Market & Provisions in Safety Harbor, Hookin’ Ain’t Easy, and P.J.’s Oyster Bar. Radigan collects an estimated 7,000 pounds of shell a month from current participants. That’s 7,000 pounds less garbage going into Florida landfills.

“And we’ve only scratched the surface of the number of restaurants that sell oysters throughout the bay,” says Radigan.

Radigan anticipates another two to three restaurants will join the program by the end of October. “Our goal is to bring in about 20 restaurants by 2026,” Radigan told CL.

“We want to bring in as many partners as we can to work with Pinellas County and other organizations to collect as much of that shell as we can, because we don’t want it to go into landfills,” Radigan continued. “We want to be able to take it and put it back into the waterways to serve as habitat for the Eastern Oyster.”

Twenty months after its inception, in September 2023, Shells to Shoreline hit a significant milestone, collecting 100,000 pounds of oyster shells.

Shells recovered in the Shells to Shoreline Program feed into Tampa Bay Watch’s decades-old shoreline restoration efforts. In the past, the organization used fossilized bivalve shells mined in South Florida for their shoreline restoration efforts. They shovel the shells into aquaculture mesh bags and stack them along the shoreline, creating substrate for oyster larvae to attach to.

Oyster larvae will attach to any hard substrate, but there’s an advantage to using fresh shells.

Oysters prefer to settle in the presence of other oysters, which they detect by smell.
“Once the oysters reach a certain age in the water column, after the eggs have been fertilized, they take chemical cues,” Radigan explains. “They chemo sense where they want to settle down. When they smell other oysters, they settle down, and that’s where they want to live.”

Tampa Bay Watch still uses fossilized shells, but they look forward to harnessing the advantages fresh shells provide.

“Now that we have the oyster shell recycling program, we lay down a base of fossilized shell to serve as a table for fresh shell,” says Radigan.

This is the setup the group used to create 1600 square feet of new oyster reef outside of MacDill Air Force Base in the first week of October.

In terms of where all these oyster shells will wind up, the possibilities are “enumerable,” says Radigan. “We have a need for them all throughout the bay.”

We followed Tampa Bay’s oyster shells from bar to bay, as Tampa Bay Watch staff and volunteers collected discarded shells from local restaurants, cured the shells to eliminate any foreign bacteria, bagged fossilized shell, and created 1600 square feet of new oyster reef outside of MacDill Air Force Base in Tampa.

See the photos below.