“Noctilluca scintillans, or ‘sea sparkle’ as it is commonly known, is responsible for the pinkish coloured slick appearance currently visible on the surface of Twofold Bay,” Bega council’s coastal management officer Kyran Crane said.

“In addition to its unique appearance, noctilluca is also a bioluminescent alga and appears as a spectacular glow in the dark blue colour at night.

“Algae generally require a mix of light, high nutrients and warm water in order to bloom, which is currently the case for this species of algae.

“The best place to observe the bioluminescence is around Cocora Beach in Eden, and we encourage people to take the time to observe this natural phenomenon while it lasts.”

Council’s environmental health officer, Greg O’Donnell, said that although some microalgal blooms were known to be highly toxic, noctilluca scintillans did not fit this description.

“Noctilluca is not harmful to humans but it has been known to cause skin itch and irritation when forming in high densities,” Mr O’Donnell said.

“We’re advising that swimmers be aware of this algae and we recommend they avoid swimming where the algae is in high concentrations.

“Twofold Bay is currently the worst affected area along the coast although smaller blooms have also been reported as far north as Bermagui Harbour and Cuttagee Lake.

“Although these algal blooms are a rare occurrence, they are perfectly natural and can play an important role in the functioning of the ecosystem.”

Marine scientist Sheree Epe from the Sapphire Coast Marine Discovery Centre said the algal blooms of this type, although not common, were a naturally occurring phenomenon.

“When conditions are just right for these organisms, that is, water temperatures are high and ocean currents are suitable, they will bloom and cause these massive aggregations,” she said.

The SCMDC collected samples of the bloom and with the help of BVSC, sent them to CSIRO Marine and Atmospheric Research laboratories in Tasmania for analysis.

CSIRO scientists confirmed the bloom was caused by the dinoflagellate noctiluca scintillans.