Researchers and US military install concrete modules with self-healing oyster reef structure in Florida’s Panhandle Bay to protect base

The hybrid reef-mimicking experiment designed by Rutgers could provide protection against storms and coastal flooding

U.S. Air Force officials installed a new kind of structure Oct. 30 in the waters of St. Andrew Bay on the shore of U.S. Tyndall Air Force Base in Northwest Florida — the first part of a Rutgers University-designed “self-healing” building reef made of custom designed concrete modules and live oysters. The reef is designed to protect the base and its population from hurricanes and tidal surges.

As visitors watched, a crane lowered part of what will eventually become a 40-meter-wide reef made up of about 800 interconnected concrete cubes. Rutgers scientists created together with colleagues from various institutions. The structures are lifted into shallow water, approximately 60 meters from the shoreline.

The concrete provides a hard substrate that oysters need to attach and is specifically designed so that more oysters will naturally gravitate to the structures over the coming year, ultimately creating resilient hybrid ‘living’ reefs.

Air Force officials are testing the experimental reef, funded by the Rifense program of the Defense Advanced Research Projects Agency (DARPA), to assess whether it provides adequate coastal defense against approaching storms. The international effort involving more than 60 researchers focuses on developing self-healing, hybrid biological and artificial reef-mimicking structures to mitigate the coastal flooding, erosion and storm damage that is increasingly impacting civilian infrastructure and personnel and the U.S. Department of Defense to threaten.

Hurricane Michael, a Category 5 hurricane that devastated the Florida Panhandle in October 2018, tore apart Tyndall’s hangars, damaged several supersonic stealth fighter jets known as F-22 Raptors and left much of the base in ruins.

“This experiment will document the ability of the Reefense modules to help protect and enhance the Bay’s coastline and make it more robust and resilient,” said lead scientist David Bushek, director of the Rutgers Haskin Shellfish Research Laboratory, and professor in the Department of Marine and Coastal Sciences at the Rutgers School of Environmental and Biological Sciences (SEBS).

Oysters grow in clusters, not as individual animals, and form natural sea walls in shallow water by adhering to each other. Such organic structures are effective protectors of coastlines, but can break apart during major storms, Bushek said. The hybrid living coastline at the center of the experiment contains both man-made and natural components that are deliberately designed to be more sustainable without adversely affecting the marine environment.

Bushek observed the installation, along with DARPA’s Reefense Program Manager Catherine Campbell and other members of the research team.

The project builds on Rutgers’ historic strength as home to the oldest and one of the best oyster farming programs in the world. A analysis by Chinese scientists considered the most comprehensive to date, two of Rutgers’ oyster scientists characterized it as second and fifteenth in a ranking of the world’s most prolific and prolific oyster researchers.

The effort also benefits from faculty members’ recent innovations in materials science, hydrodynamic modeling and what scientists call “adaptive biology.” The sentence refers to the ability of organisms to change in response to environmental pressures such as rising temperatures or increasing risks of disease.

The two-square-foot, 450-pound modules being installed will be squat and honeycomb-shaped and made of specially designed concrete with a low carbon footprint and will be covered with disease-resistant oysters bred through genomic selection. The structures are expected to stabilize and protect coastlines more effectively than natural versions.

Similar to the sound-absorbing cones in a soundproof room, the holes in the modules are designed to absorb and dissipate wave energy, protecting the underlying coast and the shallow area closer to the shoreline. The structures also force larger waves to break out further, further protecting the area.

“We wanted to develop an ecologically functional, engineered structure that provides the strength and longevity of hard structures while enabling the benefits provided by organisms that colonize the modules,” Bushek said. “As a result, we have made many discoveries and progress in science and technology in recent years. We moved the needle a lot.”

Bushek cooperates Richard Rimana distinguished professor at the Rutgers School of Engineering, who is a co-investigator on the project and is leading the development of the artificial reef. Collaborating Rutgers researchers include Distinguished Professor Ximing Guo and associate professor Daphne Munroeboth from the Haskin Laboratory and SEBS, and Hani Nassifa professor in the School of Engineering.

Dozens of scientists and engineers from universities in the US and Australia are actively participating in the collaboration.