In a bid to save its coastal bases from relentless flooding, erosion and storm surges, the US military has created a $19.4 million grant to fund a “Reefense” program. The program will bring together corals, oysters and three international teams of scientists to develop “hybrid reefs,” which combine concrete structures with living coral reefs and oyster beds to break up damaging waves.
Spending billions of dollars to repair hurricane and flood-related damage to its bases – some $9 billion in 2018 alone – the Defense Department has enlisted the University of Miami, the University of Hawaii and Rutgers University to assist in deploying these super resilient reefs.
“A lot of people are surprised that the [Defense Department] is doing this, but there are more than 1,700 military installations that are on coasts worldwide, and when they’re impacted by storms it causes billions of dollars of damage,” said Catherine Campbell, the DARPA program manager in charge of the project, “so we’re looking for ways that we can reduce the wave energy so we don’t have these severe impacts from storms.”
Coral and oyster reefs protect coastlines against flooding and erosion by dissipating wave energy very efficiently. All told, a well-placed reef can absorb as much as 97% of a wave’s energy according to one 2014 meta-analysis published in Nature Communications.
The base of these hybrid reefs will be made up of artificial concrete structures designed to mimic the wave-breaking ability of natural reefs which stack together like LEGO bricks and have rough surfaces to help corals and oysters cling onto them. The living part of the reef gives the entire structure the ability to repair itself, because the corals or oysters will grow back if they get damaged by debris or a storm.
