In 1981 scientists on the Great Barrier Reef observed an amazing natural phenomenon: the coral spawning. Thousands of eggs poured from corals, like an underwater snowstorm, and collected on the surface in a pinkish-brown slick.
Since the discovery, experts can now predict probable times of coral spawning but there still remains an air of mystery around when it occurs. The mass coral spawning is triggered 4-5 days after a spring full moon. It only happens at night, while seas are calm and water temperatures have remained above 26ºC for the month prior. But what actually triggers the event is still unknown and tell-tale signs won’t reveal themselves until 20-30 minutes before it commences!
After the coral spawns, it floats to the surface and forms a slick. Here some sperm will meet a compatible egg and produce a larvae that takes about ten days to fully mature. The larvae will swim around anywhere from two weeks to nearly two months until it finds somewhere to settle, metamorphosing into a coral polyp.
While many of the fertilised eggs are eaten by predators, some will fall on exposed rock and start a brand new coral colony.
Back-to-back coral bleaching events in 2016 and 2017 made headlines across the world, with media quick to proclaim the death of the Great Barrier Reef. But while the Reef is under significant stress, primarily from climate change, it’s still very much alive, beautiful and worth fighting for.
Apathy is the Reef’s biggest enemy. While the challenges facing the Reef are immense, it’s not too late to turn things around - but the window of opportunity is closing. We are all responsible for the Reef’s future – now is the time to unite and take real action!
#SpawningGBR is our collaborative annual showcase aiming to celebrate the beauty and resilience of life on the Reef. By allowing you to interact with data, projects and content real-time via our microsite, we hope to share the story of the spawning with the world and allow you to witness it as it happens.
It’s important to share the Reef’s good news stories to inspire people to make positive changes to help the marine park.
This year's coral spawning is a defining moment in the history of the Great Barrier Reef. The corals out there today have survived two consecutive years of coral bleaching – their genes are a genetic gold mine for the future of the Reef. We are hoping that the next generation spawned from these genes will be more resilient in the face of climate change.
Reef operators, photographers, scientists, divers and citizens from across the world are able to contribute to the spawning dataset with the Eye on the Reef app. Whether you’re a tourist on a night dive, a scientist or a fisherperson spotting a slick, everyone can play a part.
As data comes in, our interactive map lights up in real-time to show locations and sightings, allowing the world to tune in and follow the action via footage, images and reports.
If you’re one of those fortunate enough to witness this year’s spawning, make sure to share your experience by:
