Coral Reefs Revived In Large Incubators

A new method is to revive the world’s coral reefs by combining lab-grown larvae with dying corals.

NATURE Once a year, corals breed. Right after full moon and in the middle of the night, millions of small, orange-red bubbles rise from the ocean floor like “snow”. The bubbles are lumps of sperm and egg cells from corals, which are hermaphrodites. At the ocean surface, the lumps disintegrate, and eggs and cells from different colonies get together.

However, such "parties" are getting less intense, as the world’s coral reefs suffer due to climate change, ocean acidification, and fishing. More than 60 % of the coral reefs are either damaged or endangered. So, scientists are working on boosting reproduction. At the Great Barrier Reef off Heron Island, Australia, marine biologist Peter Harrison from the Southern Cross University has helped new generations of corals along for the first time by means of a new method that could assist endangered coral reefs through-out the world.

In the lab, the scientist bred millions of coral larvae. Instead of making them grow more in the lab, he placed them directly on the reef in a giant incubator – a 100 m2 net that held the larvae in place, until they settled onto the dead corals.

Scientists plan to use an even bigger net at some point, as the reefs stretch more than 344,000 km2.