This robot plants heat-resistant corals to save endangered reefs

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The climate is changing faster than many species can adapt, so scientists are trying to speed up evolution by fostering the spread of creatures who can take the heat. Think of it as natural selection with a little boost from humans — or, in some cases, robots.

To that end, Australian scientists Peter Harrison and Matthew Dunbabin recently teamed up for a world-first field experiment. A robot Dunbabin designed carried coral larvae that Harrison had gathered and dispersed them on part of the Great Barrier Reef. What makes these larvae unique — and the groundbreaking experiment especially promising — is that they are heat-tolerant, meaning they not only could survive, but flourish, in warmer waters.

Harrison had collected the larvae from corals that had survived deadly marine heat waves in 2016, 2017 and 2018. “These surviving larvae are likely to have greater ability to withstand heat stress as they survive and grow,” Harrison said, meaning they could thrive in a warmer world.

Pollution from fossil fuels is heating up the planet, rendering ocean waters inhospitable for coral. Even in the more optimistic scenarios, virtually all of the world’s reefs could be eradicated by mid-century. Ensuring the survival of these natural treasures will depend on cultivating more heat-tolerant corals. That’s where the robot, called “LarvalBot,” comes in.

“I first thought about the larval restoration concept some decades ago when I was part of the team that discovered the mass coral spawning phenomenon on the Great Barrier Reef in the early 1980s,” said Harrison, director of the Marine Ecology Research Centre at Southern Cross University. “Literally billions of coral larvae are produced during mass spawning events from healthy corals, but as coral cover and health have declined to the point where too few larvae are produced from remaining remnant coral populations, we now need to intervene to give nature a helping hand.”