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Strategic Partnerships

The team’s work evolved into a collaboration with researchers on the Defense Advanced Research Projects Agency’s (DARPA) program. The aim is to develop novel hybrid biological and engineered reef-mimicking structures to mitigate wave and storm damage, and reduce the ecological impact of current coastal protection measures.

“We’re developing hydrogels that are adhesive to underwater structures, so we can take the coral larvae when they've spawned, encapsulate them in that gel and apply the larvae directly on these artificial underwater structures,” Boothby explained. This method allows researchers to spatially control the larvae, provide them with sufficient nutrients and encourage them to grow down into the coral’s protective substrate.

The hope is that this process will lead to high survival rates, but that’s no easy task. Predators, increasing water temperatures and pollution all hinder the growth of these coastal defenders.

“Imagine trying to replant a forest, but a huge percentage of the trees you plant die without extremely active care and are continuously threatened by wildfires, underbrush growth or being chopped down,” Hughes said.

Not only is the attrition rate extremely high for new corals, but they develop very slowly, growing just tenths of a centimeter per year for certain species and taking up to to grow a reef from a group of larvae. But, Boothby said, once fragile larvae successfully establish themselves, they become self-sustaining. The task is tall, but healthy coral reefs are a natural and evolving solution to many threats, and could be for years to come.

“Corals build skeletons out of calcium carbonate, and they continue to build those skeletons over their life span, which is thousands of years for some of them,” said Boothby. “As they grow, the corals extend their skeletons toward the sunlight, so even as the sea water level rises, the corals will rise with it to remain close to the sunlight, and concrete can’t do that.”

Boothby is referring to human-made seawalls and bulkheads, structures that attempt to control erosion but degrade over time and are costly to maintain and build. Where corals will grow to meet the rise of sea levels for hundreds of years, seawalls are typically destroyed by waves in half a century.

The collaboration with the University of Miami, titled , is one of three projects funded through DARPA’s Reefense program and focuses on finding solutions for coral reefs in the Atlantic Ocean. X-REEFS researchers are currently working on the development of a model organism called Hydractinia that has similar behavior and larval stages to coral. The Hydractinia will prove useful for researchers when they can’t get their hands on real coral larvae between larvae spawns that only occur once a year. “We’ll put the Hydractinia larvae into a variety of polymers and encapsulate them, and see if they can survive and navigate to the underlying surface,” Boothby said.

The goal is that the findings from those trials will lead to further and faster developments to support coral growth in the ocean.

Cross-Laboratory Coastal Resilience Efforts

Utilizing materials science to help coral reefs grow is just one tool APL is developing as part of its larger coastal resilience toolkit. From arctic sea ice modeling to tracking carbon emissions, Laboratory researchers are leaning on the varied strengths and capabilities of sectors and departments across APL to make sustainable contributions that address national security and global challenges resulting from climate change.

“If we’re going to see how coral and oyster reefs mitigate erosion, we’re going to have to see how those waves move, and then how they change when they react with these natural structures,” Hughes said.

To do that, they’ve been working with researchers from APL’s Sea Control Mission Area and using APL’s Hydrodynamics Research Laboratory, home to a hydrodynamic tank that emulates ocean behaviors and dynamics.

“Our teammates across the Lab have been looking at modeling and modifying what hurricanes look like and what their impacts are under different conditions,” noted Hughes. “We’ve been working closely with the marine biologists in the NAMI lab to help us grow mangroves and oysters and see how they respond to our studies. It’s been fulfilling to see so many of the Laboratory’s strengths work together toward these common research goals to understand the planet.”

Just as Hughes’ initial challenge began turning wheels in Boothby’s mind to grow corals, the projects she’s working on today are already spurring future innovation with robotics and artificial intelligence applications.

“There are so many different ways we can take this research and not only make it applicable, but make it automated in the field,” Boothby said. “We’re consistently monitoring what the government is hoping to achieve and how we can best respond to those calls for action.”