Hybrid Coral Reefs Product of Global Warming, Study

A team of Australian and US scientists have discovered a solution to help corals fight climate change: hybrid reefs.

Researchers found that offspring of coral from warmer and colder waters could tolerate an increase of about 1.5 degree Celsius in water temperature. Warming and bleaching are two of the biggest threats to the world's coral reefs, which have already been affected by global warming and increased dissolved carbon dioxide in the world's oceans.

The study involved crossing coral species Acropora millepora from far northern Great Barrier Reef where the waters are warm, with same species specimens from south 540 km away, where waters are colder. The offspring had inherited heat tolerance.

The team also found that larvae had greater heat tolerance if the mothers had passed on the strain, which also suggests role of mitochondria in inheriting heat tolerance.

"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. This is occasion for hope and optimism about coral reefs and the marine life that thrive there," said Mikhail Matz, co-lead author.

Before taking up interbreeding on a big scale to ensure coral survival, researchers will have to study adaptability of heat-resistant corals in varying conditions.