COASTAL CHALLENGESDeveloping Novel Hybrid Reef-Mimicking Structures

Published 22 June 2022

Despite previous efforts to implement storm mitigation solutions — including concrete breakwaters — damage due to storm surge and flooding continues to devastate coastal areas around the world. In response to these threats, DARPA has launched the Reefense program to develop self-healing, hybrid biological, and engineered reef-mimicking structures to protect civilian and DoD infrastructure, personnel by mitigating damage related to coastal flooding, erosion and storm surge.

DARPA has selected three research teams to work toward development of comprehensive, enduring solutions to mitigate coastal flooding, erosion, and storm damage that increasingly threaten civilian and Department of Defense (DoD) infrastructure and personnel. Despite previous efforts to implement storm mitigation solutions — including concrete breakwaters — damage due to storm surge and flooding continues to devastate coastal areas around the world. In response to these threats, DARPA has launched the Reefense program to develop self-healing, hybrid biological, and engineered reef-mimicking structures to address the challenges.

Under Reefense, custom wave-attenuating base structures will promote calcareous reef organism (coral or oyster) settlement and growth, which will enable the system to self-heal and keep pace with sea level rise over time. A system will be put in place with a goal to also attract native non-reef building organisms necessary to help maintain a healthy, growing system. Finally, adaptive biology (other than genetically modified organisms) seeks to improve coral and oyster resilience against disease and temperature stress, to ensure compatibility with a changing environment.

In order to meet program milestones, DARPA has contracted with three research teams charged with developing comprehensive, enduring solutions. Research will be conducted in varying tidal current conditions in the Pacific and Caribbean/Atlantic regions:

1. The Rutgers University team (Prof. David Bushek) is focusing on oyster reefs in the Gulf Coast.

2. The University of Hawaii team (Prof. Ben Jones) is working on coral reefs in the Pacific Ocean off the coast of Hawaii.

3. The University of Miami team (Prof. Andrew Baker) is developing solutions for coral reefs in the Atlantic Ocean.

“As part of this program, performers will employ recent innovations in materials science, hydrodynamic modeling, and adaptive biology to optimize these structures for responding to a changing environment,” stated Dr. Catherine Campbell, Reefense program manager. “These protective structures aim to provide immediate protection, facilitate the growth of natural calcareous organisms, and enable rapid biological adaptation of the coral and oysters already present in the water to the new reef structure in a matter of months to years.”

Reefense performers will have the opportunity to engage with U.S. government stakeholders, including the U.S. Army Corps of Engineers, as well as appropriate regulatory authorities. Teams also are expected to collaborate with ethical, legal, and societal implications experts.