**Colonized Artificial Reef Structures May Harness Storm Power**
On October 10, 2018, Tyndall Air Force Base, situated on the Gulf of Mexico, experienced a sudden and catastrophic event—not from adversarial forces, but from the forces of nature. Hurricane Michael, which started as a Category 2 storm, quickly escalated to a Category 5 hurricane with relentless winds of 155 miles per hour. The storm devastated the base, leading to damage amounting to billions of dollars. Although Tyndall narrowly escaped flooding, the incident highlighted an escalating concern for coastal military bases: the rising frequency and severity of extreme weather, intensified by climate variability.
The U.S. Department of Defense (DoD), overseeing more than 1,700 coastal installations globally, has acknowledged the pressing necessity for creative strategies to safeguard these vital assets. Increasing sea levels and amplified storm activity are eroding coastlines and raising the likelihood of flooding. Consequently, the DoD is investigating a groundbreaking method for coastal defense: artificial reefs engineered to absorb wave and storm surge energy, while being naturally populated by organisms such as oysters and corals.
### The Impact of Artificial Reefs
Later this month, Tyndall Air Force Base will serve as the test site for a prototype artificial reef crafted by a team of researchers from Rutgers University. This reef, composed of three chevron-shaped formations, each weighing about 46,000 pounds, has been designed to diminish wave energy by up to 70%. However, what distinguishes this reef from conventional seawalls is its capacity to host oysters—nature’s natural wave mitigators.
Oysters effectively absorb wave energy thanks to their distinctive growth structures. They create substantial, robust mounds with intricate surfaces that disrupt wave energy, akin to a natural reef. Unlike static seawalls, which can be overrun by rising waters and necessitate continuous upkeep, oyster reefs possess the ability to adapt to environmental shifts, presenting a fluid and sustainable approach to coastal defense.
### The Reefense Initiative
The artificial reef at Tyndall is part of a broader program called “Reefense,” a $67.6 million initiative initiated by the Defense Advanced Research Projects Agency (DARPA). The aim of Reefense is to create “hybrid” reefs that merge artificial structures with natural organisms like oysters and corals. DARPA has appointed three research teams, all affiliated with U.S. universities, to develop and evaluate these hybrid reefs over the next five years.
Conventional coastal defenses, including seawalls and rock barriers, possess notable limitations. They redirect wave energy instead of absorbing it, often worsening erosion in neighboring zones. Furthermore, as sea levels rise and storms gain strength, these structures become increasingly prone to failure. Conversely, hybrid reefs provide a more robust and adaptable option by leveraging the natural wave-dampening capacities of oysters and corals.
### Nature as Infrastructure
The idea of employing nature for coastal protection is not a new concept. For many years, experts have acknowledged the importance of restoring coastal habitats such as marshes and mangroves to mitigate storm impacts. Specifically, oysters and corals have shown considerable potential in this context. Oysters, in particular, can grow vertically at a pace that corresponds with sea-level rise, rendering them ideal for sustainable coastal defense.
Currently, numerous oyster reefs are being established along the U.S. Atlantic shoreline, many specifically created to safeguard coastlines. Nevertheless, there remains much to uncover regarding the efficacy and cost-effectiveness of various reef designs. The Reefense initiative by DARPA seeks to bridge this knowledge gap by rigorously testing and evaluating the performance of hybrid reefs under real-world conditions.
### Hybrid Reef Deployments
The Rutgers research team has devised a prototype reef consisting of 788 interlocking concrete modules, each approximately two feet in width. These modules are crafted to dissipate wave energy through their intricate internal configurations, lowering wave strength by as much as 70%. However, the true innovation lies in the reef’s capacity to attract and sustain oyster colonies. The concrete surfaces are designed with optimal hardness, texture, and shading to foster oyster colonization, which could potentially further decrease wave energy by an additional 20%.
To guarantee the long-term viability of these reefs, the Rutgers team is also focused on cultivating disease-resistant oysters. Atlantic oysters have suffered from a protozoan ailment known as dermo, which has significantly reduced populations in recent years. Through crossbreeding oysters that exhibit natural resistance to dermo, the team aims to establish a more robust population capable of thriving amidst environmental challenges.
### Coral Reefs for Tropical Climates
While oysters thrive in temperate waters, coral reefs present the most effective protection in tropical environments. Coral reefs, like those found in Hawaii, function as natural wave barriers, dissipating wave energy over extensive distances. Motivated by this natural mechanism, a team from the University
