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Caretaker bots and starfish assassins: Meet the tech that protects Earth’s reefs

Coral reefs are dying everywhere. As the home of the most diverse ecosystems on Earth, that’s bad news. Coral reefs protect our coastlines from waves and tropical storms, while also sheltering huge numbers of marine organisms. Their decline is the result of predominantly human actions such as pollution, overfishing, coral mining and, of course, the coral-bleaching effects of climate change.

Can technology help mitigate or even reverse this tragic trend? Here are six examples of cutting-edge tech that might assist with exactly that.

Robots vs. coral predators

RangerBot: The Robo Reef Protector

Starfish may look cute and harmless, but certain types are surprisingly problematic when it comes to coral reefs. Crown-of-thorns starfish prey on coral, secreting digestive enzymes to absorb their nutrients. One such starfish can consume an astonishing 65 square feet of living coral reef every single year.

To stop them, researchers from Australia’s Queensland University of Technology, Google, and the Great Barrier Reef Foundation have developed an underwater drone called RangerBot. It’s able to navigate autonomously underwater, identify starfish with 99.4% accuracy, and then dispatch them by initiating a fatal injection. The drone can also be used for monitoring coral bleaching, water quality, and pollution, along with mapping out large underwater areas.

“We believe it will be a very valuable tool for reefs around the world,” Professor Matthew Dunbabin, a lead researcher on the project, previously told Digital Trends. “Having an easy-to-use, small underwater robot that can operate in coral reef environments fills a current technology gap to allow larger-scale monitoring and management of reefs globally. We believe this is a first step in the development of a range of visual-guided robotic systems for environmental monitoring.”

Using robots to repopulate coral reefs

QUT's LarvalBot makes first delivery of coral babies

Robots can be used for protecting coral reefs from would-be predators, but they could also be useful for helping reseed them with coral babies. This tiny coral spawn is collected in its hundreds of millions in places like the Great Barrier Reef. It is then reared into baby corals in bespoke floating enclosures, before a robot called LarvalBot delivers them to the reef to ensure the survival and thriving of coral reefs in the future. Think of it as underwater crop dusting — only with a robot controlled via iPad instead of a plane.

The robot, developed by researchers at the Queensland University of Technology, can carry enormous amounts of these baby corals. Two or three robots can carry a combined 1.4 million larvae. They can then disperse them over an area of 1,500 square meters per hour for each robot.

“We need to intervene to increase the efficiency of restoring coral communities because many of these impacted reefs now have too few adult spawning corals left alive to recover naturally,” Professor Peter Harrison, director at the Marine Ecology Research Center, who is working on the project, told Digital Trends. “By efficiently capturing coral spawn, we can maximize fertilization of the eggs by sperm and then rear millions of larvae that are then delivered to damaged reef sections using LarvalBot, so this project is an exciting combination of ecology and technology.”

NASA gamifies coral mapping

Can NASA and video games help save Earth’s coral reefs? A new project by the famed space agency seeks to find out. For the past several years, NASA has been building tools for 3D imaging coral ecosystems from the air, via a special fluid lensing system with the NASA FluidCam, attached to drones or aircraft. However, while plenty of data has been collected, the coral images still need to be properly classified before they can be used for research.

“The ultimate goal of the project is to produce the highest resolution habitat map of coral reefs around the world and help us understand the current and past status of coral reefs and shallow marine systems, in general, to better protect them into the future,” Ved Chirayath, the principal investigator involved with the project, told Digital Trends.

The initiative does not directly seek to make changes in the ecosystem like some of the others on this list. Instead, it aims to use game data to classify and assess the health of global coral reefs. The idea is that players of the game — available for both iOS and Mac — learn how to identify coral and then mark it with a brush within the game. This information is then transmitted back to NASA’s servers to help its A.I. figure out how to identify coral on its own. In part, this documenting of coral reefs around the world will make it possible to initiate more targeted interventions where required.

Reseeding reefs with … concrete pods?

Image used with permission by copyright holder

As a more efficient alternative to coral transplants, whereby grown coral is moved to other imperiled reef communities, a project by marine ecology group Secore International uses concrete pods for reseeding reefs. These small, spiky, tetrapod-shaped concrete structures, which can be seeded with coral larvae, can then be wedged into reef crevices by divers. Unlike coral transplants, this can be done in large numbers in a very short space of time. It results in a cost reduction of up to 18-fold. Researchers have been exploring the technology since 2014, mainly focused on smaller areas.

“We are … testing this technique on a range of reef habitat types, and with a range of different coral species,” Valérie Chamberland, a research scientist at Secore International based on Curacao, previously told Digital Trends. “On Curacao, we have implemented about 12 pilot sites around the island — including reefs ranging from a healthy to a degraded state — where coral offspring of a total of seven species have been outplanted using the sowing technique. While the success of this new technique varies depending on the coral species and on the environmental quality of the restoration site, the results are promising.”

Electroshock therapy for reefs

Biorock Electric Reefs grow back severely eroded beaches in months

To restore coral to its majestic glory in Granada, scientists are employing Biorock to quite literally shock coral into action. Well, kind of. Biorock reefs use an electrically conductive frame that is secured to the seabed. A low current (so low it won’t hurt any life in the vicinity) is then passed through the water. This creates an electrolytic reaction, which causes calcium carbonate to form on the reef surface. Coral fragments are then transplanted, which flourish as a result of the natural mineral crystals. The corals thrive on these substrates, where they can hit growth rates five times faster than they would normally. Today, there are dozens of Biorock Electric Reef projects taking place around the world.

3D-printed coral reefs

Shortage of actual healthy coral? Researchers from Cambridge University and the University of California San Diego recently 3D-printed coral-inspired structures that are able to grow dense populations of tiny, microscopic algae. Corals and algae enjoy a symbiotic relationship, whereby the coral hosts the algae, and the algae provide sugars to the coral via photosynthesis. The printed coral matches the natural coral structures and its light-harvesting abilities. This creates an artificial host microenvironment that could one day be used to help plug gaps in real coral reefs.

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Luke Dormehl
I'm a UK-based tech writer covering Cool Tech at Digital Trends. I've also written for Fast Company, Wired, the Guardian…
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