Future seawall panels at Bayfront Park will improve marine ecosystem

A collaborative project between the town of Longboat Key and the Sarasota Bay Estuary Program will establish new underwater homes for marine organisms at Bayfront Park. 

The $500,000 project focuses on the installation of concrete panels along about 300 feet of Bayfront Park’s vinyl seawall. The project is reaching the manufacturing stage and residents will probably see installation by the end of 2025. 

According to Science and Restoration Manager for the SBEP Ryan Gandy, the panels — dubbed mangrove panels — mimic the look and shape of red mangrove roots.

That shape, along with the concrete material, will help the recruitment of marine organisms like oysters, barnacles and more. 

Gandy said new vinyl seawalls do not allow for organisms like oysters and barnacles to attach as well as they do to concrete seawalls. The reason why remains up for speculation, he said, but fewer of those organisms can be detrimental. 

“When we replace living shorelines like mangroves and flats and things like that with a hard, concrete surface, you lose a lot of those ecosystem services that environment provides,” Gandy said. 

The removal of these habitats leaves a “clean slate” and, while the vinyl seawalls do recruit organisms, it’s at a much slower rate, Gandy said. 

That’s where the concrete mangrove panels come in. 

“By adding this 3-D structure there, we’re hopeful that it adds some of that depth and complexity where these critters can hide from predators, where they can grow and then contribute back to the ecosystem,” Gandy said.

Organisms like oysters and barnacles are filter-feeders, meaning they draw in water, collect nutrients and release the water. This process filters the water — hence the name — and can improve water quality over time. 

For example, some studies estimate that one adult oyster can filter up to 50 gallons of water per day, according to the National Oceanic and Atmospheric Administration. 

Project progress

Interim Director of Public Works Charlie Mopps said the town and SBEP finalized the design of the panels in December.

KindDesigns designed and will manufacture the mangrove panels used in the Longboat Key project. 

Now, Gandy said the project team is working with a contractor to discuss the best method of attaching the panels to the vinyl seawalls. 

The attachment will need to be secure enough to withstand wave action

Courtesy image

but also have enough space in between the panel and the wall to allow for hiding spaces for larger organisms like fish. 

With the design finalized, the project team will move onto the permitting phase once the attachment method is worked out. Then, KindDesigns will ramp up production on the mangrove panels. 

The panels will be at Longboat Key’s public park, Bayfront Park, where residents and visitors can see the mangrove panels in action. Gandy said the project could serve to show how this type of project could be applied in other places. 

“This is a demonstration project to show this concept and then we can look at it over time and see how it’s doing,” Gandy said. “Then it potentially provides something that, if a homeowner wanted to add some structure to their shoreline, they can do that.”