Stunning images have emerged from Tasmania showing the sea glowing a rare electric blue.
Photographs taken off the island's north coast show the bioluminescent waters caused by noctiluca scintillans or sea sparkle as it is commonly known.
When waves or currents disturb the billions of single-celled algae or plant plankton, the tiny cells flash, illuminating the water around them.
It is thought the flashing mechanism is deployed to scare off predators.
While the phenomenon is not harmful to humans, the organisms eat other species, and so if there is a large amount of it, it will eat all the other plankton.
Sea sparkle was first reported in Sydney Harbour in 1860, hundred of miles to the north.
However, since the year 2000 it has moved southwards due climate change causing the oceans to become warmer, and also due to currents in the water.
Sea sparkle can also be sighted in Puerto Rico, Jamaica and California.