Defending the Shore

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Their inventors compare them to air bags or speed bumps in the sea. And they just might be the future of fighting coastal flooding in Florida.

They’re called Seahives, and they’re a new kind of artificial reef being developed and field-tested by researchers at the University of Miami. They’re 18-foot-long, hexagonal-shaped hollow tubes that get stacked in pyramid-like shapes on the seafloor just offshore. The 2,500-pound concrete structures are perforated to allow seawater to flow through them.

The goal of these devices is twofold: Dissipate wave energy and slow down potentially destructive waves before they hit the shore, while simultaneously providing a hospitable environment to grow corals or mangroves.

They’re designed to be a win-win: Reduce flooding, build habitat.

In March and August 2023, clusters of Seahives were installed at two pilot projects at Miami Beach and Pompano Beach, where they’re currently being studied and evaluated. Miniature versions had previously been tested successfully in a giant water tank, but this is the real thing.

“They slow down the waves. They minimize wave height and energy, so when the waves hit the shoreline, they’re shorter and less powerful, so we don’t have a lot of over-topping and coastal flooding. This also reduces the frequency of beach renourishment projects,” says Diego Lirman, an associate professor of marine biology and ecology at the University of Miami’s Rosenstiel School of Marine, Atmospheric, and Earth Science.

The technology shows enough promise that Miami is one of three universities sharing a $22-million grant from the Defense Advanced Research Projects Agency (DARPA), a branch of the U.S. Department of Defense. The researchers will be scaling up their project to see if their designs can help protect military and civilian coastal infrastructure.

“The purpose is to design hybrid natural and manmade structures to protect Department of Defense infrastructure in low-lying coastal areas where it’s at risk. They have a huge amount of assets that are vulnerable to sea level rise and storm impacts,” says Brian Haus, professor and chair of ocean sciences at the Rosenstiel School. “The things we learn here will certainly be applicable to civilian infrastructure as well.”

The project got started in 2018 when a group of the university’s researchers joined forces to develop artificial reefs combining natural and manmade elements — otherwise known as “green” and “gray” elements. Forming a project called EcoReef, they received funding from the university’s Laboratory for Integrative Knowledge, the city of Miami Beach and the National Cooperative Highway Research Program.

“The idea was to investigate these tubes and see if they can dissipate wave energy,” says Landolf Rhode-Barbarigos, an assistant professor in UM’s Department of Civil, Architectural and Environmental Engineering, and one of the project’s lead investigators. “Would this be a viable technology, and in what configurations?”

Seeking to slow down waves, they tested out small-scale versions of different-shaped hybrid reefs in the university’s 75-foot-long, 38,000-gallon Alfred C. Glassell Jr. SUSTAIN Laboratory wind-wave tank.

“We place a scale model of a structure into the water and we run waves over it, and we measure the waves before and after the structure to understand how much the waves are being reduced,” says Haus, who oversees the wind-wave tank.

Based on the results, the team chose the honeycomb-shaped Seahive units and installed them last year in two South Florida locations:

Miami Beach

In March 2023, a cluster of 27 interlocking Seahives were placed together to create an artificial reef 1,000 feet offshore of North Beach Oceanside Park in Miami Beach. They’re in 14 feet of water, with the tops of the Seahives six feet beneath the water’s surface, Lirman says.

As the honeycomb-shaped reefs get acclimated to their underwater environment, corals grown at the Rosenstiel School’s nurseries are being attached to them. The intent is to replace some of the area’s coral reefs that have been killed off by disease or bleaching. So researchers are choosing the toughest, hardiest corals they can find.

“There are coral experts that are designing or selecting the right corals that are more heat-tolerant, that are dissipating more wave energy, that are the Michael Jordans of corals,” Rhode-Barbarigos says.

There’s another benefit: Research shows that healthy coral reefs can help buffer the energy from waves, reducing coastal flooding. Corals can also regrow and repair themselves when damaged.

“One of the great hopes of using this type of approach is that the corals will continue to grow as the water levels increase, keeping up with sea level rise,” Haus says, “and that the corals may be self-healing to some extent when impacted by storms.”

Pompano Beach

In August 2023, another cluster of Seahives was installed at Wahoo Bay, a new underwater marine park and living laboratory in Broward County. Unlike the Miami Beach artificial reef, this one is right next to the shoreline, where the Seahives are stacked against a seawall. They’re functioning like riprap — piles of rocks at the base of a seawall that break up the force of waves and help prevent shoreline erosion. The Seahives at Wahoo Bay will act as a buffer while also functioning as habitat. Instead of coral, researchers will be planting mangroves in this installation.

“This is a hybrid living shoreline that’s in front of a seawall,” Rhode-Barbarigos says. “On the top, our idea is to transplant mangroves to provide habitat.”

Hopefully in the future, these Seahives will be blanketed in mangroves, sponges and barnacles, attracting abundant species of fish, turtles and manatees. And ideally, down the road, Seahives will evolve into a cost-effective way for coastal communities to help protect themselves from erosion and storm surge. That’s the ultimate goal, although it’s still early in the process.

In the meantime, both the Miami Beach site and the Pompano Beach location are being monitored by divers and drones as well as wave sensors and current meters.

“The U.S. Geological Survey has deployed instruments within these structures to measure their wave mitigation properties,” Lirman says. “Soon we’ll have an amazing data set that will show us the role that these artificial reefs can play in coastal protection in an area where it really matters — because the shoreline of Miami Beach is probably the most vulnerable in the whole U.S.”

While the research group continues collecting data at these sites, their next step will be to use DARPA grant money to deploy a significantly larger, 160-foot-long artificial reef made of Seahives. If they obtain the necessary permits, that project might happen later this year at Elliott Key, the northernmost of the Florida Keys and part of Biscayne National Park.

“This is why the pilot projects are very important, because you cannot assess this purely in a laboratory,” Rhode-Barbarigos says.

Private Firms Try Their Hand

Private companies are collaborating with the University of Miami, trying their hand at manufacturing Seahives using three different methods: dry cast concrete, wet cast concrete and 3D printing, says Landolf Rhode- Barbarigos, an assistant professor in the university’s College of Engineering.

“We have intentionally been in stealth mode to complete R&D and pilot projects to gather data,” says Fredrik Wannius, co-founder of the Pompano Beach company 1Print. “We are currently working on commercializing the Seahive technology into various applications such as seawalls, breakwaters, artificial reefs and other types of green/gray infrastructure products.”

The company is manufacturing Seahives as well as housing with large-scale 3-D concrete printers and automated construction and is building out its production capabilities to work on a larger scale.

The cost of a Seahive can vary greatly, Wannius says, depending on how many are being ordered and how and where they’re being deployed. “It’s like asking, how much does a car cost?” he says. “Our goal is to make everything cost-efficient. If it’s a very large project, maybe we even move the printer to the site.”

Wannius’ startup is a member of the newly designated South Florida Climate Resilience Tech Hub, which was created in October. A consortium of local governments, businesses, universities and organizations, it’s one of 31 tech hubs nationally. It means the region can count on $50 million to $75 million in federal funds for developing and scaling innovations related to “Sustainable and Resilient Infrastructure (SRI) solutions for the global climate crisis,” according to a White House announcement.

With the Seahive technology showing promise, 1Print has received a $1.9-million grant from the U.S. Army’s Small Business Innovation Research Program. The company, along with another contractor, also won a $1.26-million contract to build artificial reefs in Okaloosa County in the western Panhandle. The cities of Destin and Fort Walton Beach are becoming snorkeling and scuba destinations due to Okaloosa County’s bustling artificial reefs program, with the ongoing deployment of more than 100 artificial reef sites offshore. 1Print is currently making the reefs it will install there.

Is the technology proven? “The data is there,” Wannius says. “Now, this is the first proof of concept on a larger scale that we’re doing.”

• Polk County Hydrogen Plant

Rocket fuel will soon be manufactured in Polk County at Florida’s first “clean carbon” hydrogen plant. Construction started in June on the $100-million plant on the outskirts of Mulberry. It’s being built under a memorandum of understanding between Florida, South Korea-based LowCarbon Hydrogen Corp., Tampa-based Ocean Green and Space Florida. Most of the funding is coming from LowCarbon, which is building the plant to support Florida’s growing space program. They plan to pipe hydrogen to Space Florida in Brevard County as well as the state’s urban hubs. The agreement also calls for LowCarbon to establish a research hub for clean hydrogen tech in Florida.

• Sustainability School

Recognizing the critical intensification of environmental issues in South Florida and beyond, Florida Atlantic University in October launched its new School of Environmental, Coastal, and Ocean Sustainability (ECOS). A partnership between FAU’s Charles E. Schmidt College of Science and FAU’s Harbor Branch Oceanographic Institute, the school includes an array of disciplines and creates a comprehensive environmental hub at the university.

“We are in a prime location to study the environment and its intersection with urban areas — with the Atlantic Ocean, the Indian River Lagoon, the Everglades and numerous freshwater ecosystems converging in the largest metropolitan area in the state,” says Valery E. Forbes, dean of the College of Science.

Colin Polsky, professor of geosciences and director of FAU’s Center for Environmental Studies, will serve as founding director of the ECOS school.

• Shade Solution

Palm Beach County received a $1-million grant from the Environmental Protection Agency in November to plant trees in six county parks, host tree giveaway events and establish an urban food orchard.

“Local parks play a critical green infrastructure role,” says Jennifer Cirillo, the county’s parks and recreation director. “We are thrilled to work with our partners to increase tree canopy in the Glades Region (in western Palm Beach County), further mitigating the urban heat island effect, making our community more climate resilient and providing additional wildlife habitat in our parks.”

Public workshops hosted by the county’s Office of Resilience revealed that residents “wanted to see more shade trees invested in their parks,” says Megan Houston, the county’s resilience director.

Across the state, Colony Cove, a 55-and-older mobile home community in Ellenton in Manatee County, won the Manufactured Housing Institute’s Leadership in Sustainability Award for 2023 for its tree-planting efforts.

In collaboration with Sarasota Urban ReForesters (SURF), more than 150 Colony Cove residents and employees planted more than 4,000 trees on a 1.5-acre peninsula located within the community, creating an environmentally beneficial microforest.

• Renewable Research

The University of North Florida is collaborating with JEA, Jacksonville’s community-owned utility, to open the JEA Sustainable Solutions Lab. The lab, which includes a five-year, $500,000 financial commitment from JEA, will give students the chance to research renewable energy and clean water technologies.

As part of the collaboration, UNF students will work with JEA experts on clean energy projects, while JEA staff and UNF faculty will jointly develop academic programming related to green energy.

Tags: Feature, Climate Sustainability & Energy