Grant Houghton was taking an evening walk with his wife along Rushcutters Bay on Sydney Harbour when a faint glow in the water caught his eye.
He stopped and looked more closely, noticing small green flashes appearing around fish when they stirred the water.
Then he decided to toss in a stick, and said what he then saw was “surreal”.
“When I threw the stick in the water it created the splash which was like an explosion of colour, this bright majestic green, it almost looked like a firecracker,” Mr Houghton said.
“It was nothing like I’ve ever seen in nature. So surreal, it almost felt like stepping into a sort of a dream world.”
What the pair witnessed was a bioluminescence event, created by a glowing type of single-celled algae called phytoplankton which blooms in warmer waters.
“It just gave us this sort of childlike sense of awe that you don’t normally get as an adult,” he said.
A hit with bioluminescence enthusiasts
He posted a photo on a Facebook group called Bioluminescence Australia, and enthusiasts from across Sydney have been travelling to the spot over the past week to see the bright green splashes for themselves.
“A bunch of people had driven out that night, all the way from midnight to three am, throwing sticks and looking at this event,” Mr Houghton said.
“There was this other couple who had driven out from Hornsby, it must have been 45 minutes later at night, just to see if it was still there.”
Professor Iain Suthers from the School of Biological, Earth and Environmental Sciences at the University of New South Wales said the phytoplankton creating this effect is known as noctiluca, which means night light.
“There’s a whole sequence of seasonal events happening in the ocean, when the nutrients, the temperatures and the light levels are just right for the phytoplankton to bloom,” Professor Suthers said.
