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Corals Have the Genes to Adapt to Warmer Oceans

Migration and breeding may enable coral to adapt to hotter oceans, according to research published in Science.

Researchers from the Australian Institute of Marine Science and the University of Texas at Austin crossed individuals of branching coral Acropora millepora from the far north of the Great Barrier Reef with members of the same species at Orpheus Island, 540 km further south, and found that temperature tolerance from the northern coral was passed to the offspring.

The coral larvae had up to a tenfold increase in their chances of surviving heat stress, of which fivefold was contributed maternally. Genetic analysis revealed that tolerant larvae had altered expression of mitochondrial genes, which are inherited solely from mothers.

“This discovery adds to our understanding of the potential for coral on the Great Barrier Reef to cope with hotter oceans,” says joint senior author Dr Line Bay.

“Averting coral extinction can begin with something as simple as exchange of coral immigrants across latitudes, which will happen naturally through larval dispersal but can be jump-started by humans moving adult corals,” says co-lead author Prof Mikhail Matz of the University of Texas at Austin.

The researchers point to the potential to identify and protect reefs with heat-tolerant coral communities so that they can be propagated artificially and used to repopulate other reefs.