Eggs discovered in bleached coral birth new hope for Great Barrier Reef
A NEW, very welcome discovery, has inspired fresh hope for Australia’s Wonder of the World.
Tiny sacs of white eggs in bleached coral have been found by researchers from the Australian Institute of Marine Science (AIMS).
Researchers diving on reefs between Townsville and Cairns, some of the worst affected areas of bleaching, were assessing the mortality and survivorship of the region when they made their find.
The eggs are still developing, but this indicates that the bleached corals are preparing to spawn again.
The AIMS scientists were surprised, yet thrilled to see these early signs of life.
Coral biologist Dr Neal Cantin said: “We travelled to 14 reefs between Townsville and Cairns, including Fitzroy Island where we saw surviving coral producing eggs, which was not expected at all.
“Previous studies have shown a two to three year delay in reproduction after severe bleaching but at most of the reefs we are finding colonies of Acropora [branching hard coral] colonies with early signs of egg development in shallow waters, 3m to 6m deep.”
The project’s team leader Dr Line Bay added, “The majority of coral colonies on the inshore reefs have regained their colour and the growth of some colonies was so good they had overgrown our original research tags.”
Sadly, it’s not all good news.
“Some of the more sensitive corals are now rare even in areas where they had been abundant in March,” Dr Cantin said.
The AIMS team will now test whether the eggs are able to be fertilised.
“There is concern the eggs may not be able to successfully fertilise and develop into coral larvae,” Dr Cantin said.
“The eggs are now white, and just before the spawning event they should turn pink when they are preparing for the spawning.”
The annual spawning event is due on the full moon of December 5. Dr Cantin said each coral could produce eight to 12 eggs per polyp in colonies of thousands of connected polyps.
While this is welcome news, the reef still has a long road to recovery.