The floating larval pool captured millions of future coral babies on 21 November. Photo: Great Barrier Reef Foundation.
A cutting-edge coral restoration technique is bringing new life to the Great Barrier Reef after a mass bleaching event caused by Tropical Cyclone Jasper and a marine heatwave.
Triggered by the November full moon, the largest annual spawning event on the planet took place on 21 November as corals released trillions of eggs and sperms into the water in a mass breeding phenomenon.
This year, a game-changing technique known as coral IVF was brought to the Far North Queensland.
Great Barrier Reef Foundation coral reef restoration director Melissa Rodgers said there was a significant amount of luck involved in spawns growing into healthy corals, adding the technique would increase the chances by 100-fold.
“Essentially, what we do is when coral spawns and bundles of sperm and eggs are released, we collect those in specifically designed larval pools, and then the sperm and eggs need to meet and become larvae,” she explained.
“In nature, they would float along on currents and develop and settle onto a coral reef, but there’s so much chance involved in that process and that larvae becoming competent at the right time, and then settling in the right place on a reef that doesn’t have algae or sediment in the way.
“The technique we’re using allows the larvae to become ready to settle, and then we essentially direct them to where we want them to settle on the reef.”
Ms Rodgers said the reef was under threat, especially during the warmer months, so it was important to take a proactive approach.
“Cyclones and bleaching do impact the health of the reef, which is why reef restoration is so important to help enhance the resilience in terms of the upcoming summer,” she said.
New data from the Australian Institute of Marine Science (AIMS) showed the 2024 mass coral bleaching event caused the largest annual decline in hard coral cover in the northern Great Barrier Reef since surveys began 39 years ago, with initial monitoring results between Cooktown and Lizard Island revealing more than a third of hard corals had been lost to bleaching.
AIMS’ long-term monitoring program leader Dr Mike Emslie said he had hope the new generation of corals would survive the upcoming wet season, but admitted it was difficult to predict.
“It’s too early to say whether there will be any cyclones across the next few months and how they may impact young corals, however, observations by our team suggest that young corals can sometimes survive cyclones due to their small nature and cryptic habits,” he said.
Coral IVF is increasing the chances of successful fertilisation after the 2024 coral spawning event . Photo: Calypso Productions.
