The Rutgers-designed hybrid reef-mimicking experiment could provide protection against storm surges and coastal flooding

US Air Force officials on October 30 installed a new type of structure in the waters of the Gulf of St. Andrew, on the shores of Tyndall US Air Force Base in northwest Florida – the first section of the “self-healing” designed by Rutgers University. reef made from custom designed concrete modules and live oysters. The reef is designed to protect the base and its people from hurricanes and tidal waves.

As visitors watched, a crane lowered a segment of what would eventually become a 160-foot-wide reef composed of about 800 interlocking concrete cubes, created by Rutgers scientists with fellow collaborators from several institutions. The structures are erected in shallow water about 200 feet offshore.

The concrete provides a hard substrate that the oysters need for attachment and is specifically designed for more oysters to naturally gravitate to the structures over the next year, eventually forming “living” hybrid reefs.

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

Hurricane Michael, a Category 5 hurricane that devastated the Florida Panhandle in October 2018, destroyed Tyndall’s hangars, damaged several supersonic stealth fighters 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 gulf shoreline and make it more robust and resilient,” said the lead scientist. David Bushek, director of the Rutgers Haskin Shellfish Research Laboratory and professor in the Department of Marine and Coastal Sciences in the Rutgers School of Environmental and Biological Sciences (SEBS).

Oysters grow in groups, not as individual animals, and form natural dykes in shallow water by attaching to each other. Such organic structures are effective shoreline protectors, but can break during large storms, Bushek said. The hybrid coastline at the center of the experiment contains both man-made and natural components intentionally 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 the historic strength of Rutgers, home to the oldest and one of the best oyster breeding programs in the world. A analysis by Chinese scientists considered the most comprehensive to date, it featured two of Rutgers’ oyster scientists as second and fifteenth in a ranking of the world’s most productive and prolific oyster researchers.

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

Squat and honeycombed, the two-square-foot, 450-pound modules being installed are made of a specially designed, low-carbon concrete and will be topped with disease-resistant oysters bred through genomic selection. The structures are expected to stabilize and protect shorelines more effectively than natural versions.

Like sound-absorbing cones in a soundproof room, the holes in the modules are designed to absorb and dissipate wave energy, protecting the shore below and the shallows closer to shore. The structures also force larger waves further out, further protecting the area.

“We wanted to develop a functional, engineered ecological structure that would provide the strength and longevity of hard structures while facilitating the benefits provided by the organisms that colonize the modules,” Bushek said. “In doing so, we have made a lot of discoveries and advances in science and technology over the past few years. We pushed the needle a lot.”

Bushek works with Richard Rimandistinguished professor at the Rutgers School of Engineering, who is the project’s co-investigator and is leading the development of the engineered reef. Collaborating Rutgers researchers include Distinguished Professor Ximing Guo and associate professor Daphne Munroeof both Haskin Laboratory and SEBS and Hani Nassifprofessor at the School of Engineering.

Dozens of scientists and engineers from universities in the US and Australia are active participants in the collaboration.