SOFT corals have started spawning on the Great Barrier Reef, with a blizzard of sperm and eggs released into the water off the Cairns.
The main event of the annual biological phenomenon is expected to be triggered tonight and tomorrow, as hard corals simultaneously release their sex cells for mass fertilization.
Marine biologists were based on Sunlover's Moore Reef pontoon last night to capture the video of the night-time event.
Calypso Production's Stuart Ireland, who has been shooting every year since 1996, likened the event to swimming through an upside down snowstorm.
"The spawn varies from small to tiny pink and mauve balls which represent either eggs or bundled egg and sperm masses, while cloud-like white slicks or smokers represent individual male colonies," he said.
"I like hunting down the individual colonies, it's like playing join the dots.
"However, currents and the reef topography make this extremely challenging.
"Often you will find the spawn floating through the water, but be unable to trace it down to the release colony, or the colony may have just finished."
He said the special event showed that the Great Barrier Reef was resilient despite the
challenges that man and climate change had been thrown at the World Heritage Area.