Coral spawning: All hands on deck for the Great Barrier Reef baby boom
Tourism operators and local Reef industry worked through the night during the most remarkable spawning event on the planet, learning cutting-edge coral restoration techniques to help boost healthy coral numbers.
The annual coral spawning event, triggered by the November full moon, sees the Great Barrier Reef’s magnificent corals burst into life in an underwater ‘snowstorm’ by releasing trillions of eggs and sperm into the water in a mass breeding phenomenon, which Sir David Attenborough describes as ‘one of the greatest of all natural spectacles’.
This event is also the most important day of the year for coral scientists as they explore innovative methods to scale up reef restoration to protect this natural icon from the increasing impacts of climate change.
To boost the numbers of coral babies produced from this year’s spawning, a team from the Australian Institute of Marine Science (AIMS) is for the first time training Cairns and Port Douglas marine industries – including tourism – on how to use the innovative coral larval seeding technique known as Coral IVF. This overnight mission to capture millions of coral eggs and sperm in specially designed floating larval pools set up in two different locations in the region, aims to support the Reef’s natural regeneration process.
The delicate spawn bundles will stay in the nursery pools for up to a week as they develop into coral babies. Once ready, they will be placed onto reefs which include locations that have been impacted by recent bleaching events, where they can grow into healthy young corals and help bring new life to the Great Barrier Reef.
Scientists estimate that Coral IVF boosts successful coral fertilisation rates by 100-fold — raising the chances from one in a million in natural settings to one in 10,000 through this innovative technique.
Great Barrier Reef Foundation Managing Director Anna Marsden said: “Last summer our Great Barrier Reef experienced another devastating bleaching event, highlighting again that coral reefs are on the frontline of climate change. It is critical to develop a toolkit of solutions to help us restore what’s been lost and protect what remains from the impacts of climate change.
“This collaboration between scientists and tourism operators, known as Boats4Corals, was successfully piloted in the Whitsundays through our Reef Islands Initiative and is cracking through one of the biggest bottlenecks in reef restoration – scale. Off the back of this success, with support from Qantas, we’re taking the same approach to other areas of the Reef. By empowering eager tourism operators and locals to add this technique to their current conservation toolkit, we’re hoping to expand a local reef restoration movement that is grounded in science and is scalable.
“By combining the tourism and marine industry’s leadership, vessels, local expertise and people power, we’re aiming to achieve reef restoration on a much larger scale than researchers alone could accomplish. This is truly a powerful partnership.”
New data this week from AIMS Great Barrier Reef surveys in the north shows the 2024 mass coral bleaching event has caused the single largest annual decline in hard coral cover in the Lizard Island area since surveys began 39 years ago. Initial monitoring results from in-water surveys between Lizard Island and Cairns show more than a third of hard corals were lost to bleaching. Scientists are continuing to survey areas across the Great Barrier Reef and a full assessment will be published in 2025.
AIMS Principal Systems Engineer and Program Director Dr. Mark Gibbs said: “It is great to be training with new local industries on the water last night and sharing information about reefs in the Cairns and Port Douglas region.
“We’ve had very successful spawning activities, and the pools are now full of developing coral larvae. Despite the losses that the reefs in this region has sustained from summer, we are heartened by the level of spawning we’ve seen in this area.
“The approaches we are using have been developed through the collaborative Reef Restoration and Adaptation Program. While they continue to be refined, our team is using the power of local people, vessel and skills, putting them through their paces to ensure they can be translated from research into reality.
“We’ve been working with these local crews over recent weeks, and each of the different industries bring their own unique strengths and capabilities which we are harnessing together.
“While the spawn collection may be over, we are continuing to train local operators to monitor the developing corals and distribute them onto local reefs when ready. So there’s plenty of training and collaboration to come over the coming weeks.”
The Great Barrier Reef is Australia’s largest and most valuable natural icon with Deloitte’s researchshowing that the Great Barrier Reef contributes $6.4 billion to the Australian economy, sustaining over 64,000 jobs with the majority of these being from tourism activities.
Quicksilver Group’s Environment & Compliance Manager Phil Coulthard said: “Site stewardship programs to look after our local reef sites have been a core focus for the Quicksilver Group historically, however to boost resilience against future environmental stresses, there needs to be co-operative actions within the marine tourism industry and through partnerships with other industries, government, traditional owners and of course our science community.
“Projects like this are the perfect example. The last few weeks have been an incredible opportunity for our team to work alongside other industry operators and the Australian Institute of Marine Science to learn more about coral intervention techniques which we hope will not only benefit reefs locally, but also become a platform for expansion projects both here on the GBR and for reefs worldwide.”
“But the highlight of course was the chance to again witness the world’s greatest synchronized spawning event out at Agincourt Reef off Port Douglas. The sheer scale of the event was awe-inspiring and is a testament to the resilience and beauty of our Great Barrier Reef. To witness billions of individual animals managing to release smelly eggs and sperm at the same time is not only a miracle of nature, but also reinforces the delicate balance of our marine ecosystems and their dependence on environmental predictability.”
GBR Biology Manager Dr. Eric Fisher said: “Building partnerships between private industry, researchers and Traditional Owners is critical to assisting natural coral reef resilience and future proofing the Great Barrier Reef. GBR Biology is committed to supporting the Coral IVF program. It fits seamlessly alongside our existing site-assisted reef recovery programs such as coral predator control, water mixing and coral rubble stabilisation.”
This trial is funded by the Australian Government’s Reef Trust and the Australian Institute of Marine Science, with support from Qantas through its 10-year $10 million partnership with the Great Barrier Reef Foundation.
Qantas Acting Chief Sustainability Officer Fiona Messent said: “Connecting customers, from near and far, to our incredible natural landscapes is at the heart of what we do. We are proud to support the expansion of the Boats4Coral collaboration through our partnership with the Great Barrier Reef Foundation so that tourism operators and scientists can work together with the aim to scale reef restoration and help protect Australia’s natural icon.”
The project uses innovations developed through the Reef Restoration and Adaptation Program which is funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation and is also supported by Qantas.
Reef Restoration and Adaptation Program Executive Director Dr. Cedric Robillot said: “The speed at which climate change impacts are unfolding on coral reefs around the world is alarming. This knowledge-sharing and collaboration in the Cairns and Port Douglas region represents a critical step to translate the scientific innovations pioneered by the Reef Restoration and Adaptation Program into a toolkit of on-ground solutions.
“This will be achieved through a multi-year and larger scale pilot deployment to establish a future reef restoration and adaptation industry which could see reef communities, industries, Traditional Owners and managers deploy millions of corals with a higher heat-tolerance onto the Reef every year.”
About the Great Barrier Reef Foundation
The Great Barrier Reef Foundation is creating a future for the world’s coral reefs by restoring reefs and coastal habitats and helping them adapt to the impacts of climate change. We’ve built a collaborative organisation to raise funds, invest in innovative ideas and design real-world, scalable conservation programs that are delivering breakthroughs in marine and terrestrial restoration. Walking in step with First Nations people and front-line communities, the Foundation is fast-tracking and deploying solutions around the world.
Why does coral spawning matter?
No one explains it better than Sir David Attenborough:
None of the Reef's residents would be here without one truly extraordinary event. It occurs just once a year and is one of the greatest of all natural spectacles. It wasn't until the 1980s that scientists discovered it, here on the Great Barrier Reef. On a few nights of the year when the conditions are just right, all along the length of the Reef, corals of many different species suddenly erupt. It's the great spawning event and it's one of the wonders of the natural world. It's the one time in the year when the corals themselves don't just grow by branching, but reproduce sexually, and it's vital for the survival of the Reef.
What is coral spawning?
Coral spawning is when new life begins on the Reef. It occurs once a year in a mesmerising natural phenomenon that has been described as an underwater snowstorm. In late spring, corals on the Great Barrier Reef release eggs and sperm that come out as little balls that float to the ocean surface in slow motion. Spawning only occurs at night when the plankton-eating reef fish are sleeping which reduces the risk of the eggs being eaten.
It creates a pink-brown slick on the surface where the spawn will meet a compatible egg and produce a larvae that takes about ten days to fully mature into a coral polyp. Many of these tiny bundles will become young corals, providing hope for the future of our Great Barrier Reef.
Coral spawning was not discovered until 1982 at Magnetic Island. Inshore reefs tend to spawn a month ahead of the outer reef where the spawning is more spectacular. It generally occurs on the outer reefs off Cairns and Port Douglas two to six nights after the November full moon when water temperatures are 27-28C.
Photo Credit: Great Barrier Reef Foundation
