Authorities have warned water-goers to steer clear of another sea sparkle bloom off the coast between Point Lonsdale and Torquay.
Noctiluca scintillans could cause severe reactions, Department of Environment, Land, Water and Planning regional commander Aaron van Winden warned.
“Direct contact may cause allergic reactions such as skin rashes or itchiness, sore ears or nose, or if swallowed, gastroenteritis, nausea and vomiting,” he said.
“Wash immediately with fresh water if you do come in contact with sea sparkle and seek medical advice if experiencing illness after contact with affected water.”
During daylight the masses of tiny organisms appear as a murky red, pink or orange sludge floating on the water’s surface.
“When present, blooms produce a spectacular glowing light at night, however, as a precaution, members of the public are advised to avoid direct contact with affected water,” Mr van Winden said.
Sea sparkle is a common bioluminescent organism and during blooms can produce toxic levels of ammonia that can lead to fish deaths.
Affected water can become temporarily discoloured and have an unpleasant smell.
The bloom was currently one to two kilometres from the shore, Mr van Winden said.
“The bloom does not appear to be impacting local beaches at this time, however we are monitoring the situation closely for any changes.”
There have several sea sparkle blooms off the Surf Coast and Bellarine Peninsula over the past three months, including a trail several hundred metres long between Jan Juc and Torquay last month.
A department spokesperson was unable to say if the latest bloom was directly related to last month’s event.