As the climate warms, coral reefs are some of the world’s most vulnerable ecosystems. They face a triple threat of waters that are becoming warmer, more acidic, and more prone to destructive tropical cyclones. Meanwhile, corals themselves can’t easily relocate, and they don’t reproduce or re-grow very quickly at all.
This is bad news in coral-dependent economies like Hawaii and Australia. The latter’s Great Barrier Reef isn’t only a World Heritage Site, it also generates nearly $7 billion a year in tourist and fishing income. But due to pollution, climate change, and other stresses, already half of its coral has died off over the last three decades. The worry is the rest won’t survive the next three.
Because increasing protection alone won’t save the corals, a team of marine biologists from the Australian Institute of Marine Sciences (AIMS) and Hawaii Institute for Marine Biology are turning to a creative idea: breeding climate-proof corals.
The work is centered at Australia’s National Sea Simulator, a high-tech aquarium facility with massive 5,000 liter tanks and precise, computer-controlled conditions that are meant for long-term coral experiments. There, researchers will grow three generations of corals in tanks that are tuned for pH and temperature conditions expected by 2050 and 2100.
"The goal is to test the adaptive capacity of corals," says Neal Cantin, an AIMS research scientist, "to see if they can adapt to a long exposure to future climate change conditions and transfer inheritance of more tolerant traits to their offspring."
The science behind the work—that species can inherit environmentally adapted traits from their parents—is called epigenetics, and it’s already been shown to work in plants. The researchers plan to take the corals that most successful adapt and breed them together, helping evolution further along. The team is not the only to try a genetic approach to saving corals: Another, Mary Hagedorn at the Smithsonian Institution, is working to create a coral sperm bank.
Still, whether they’ll be able to cope at all is uncertain. Cantin believes some can handle the levels of acidification they will be exposed to, but he’s "less optimistic" about whether they’ll be able to adapt to two degrees of warming. The experiment, backed by the foundation of Microsoft co-founder Paul Allen, will go on for 4 to 5 years to find out.
Ultimately, if the project is successful, the goal is to create super-resilient corals that can be used to restore damaged reefs, slowly building an ecosystem that could better withstand the effects of climate change. There would be some risks, Cantin says, such as making sure to not introduce foreign microbial pathogens. And of course, Great Barrier Reef marine park managers would have to endorse the transplant work. Says Cantin: "We’re seeing if there’s enough evidence that it’s of value."