Mysterious substance in Aussie creek turns water electric blue: 'Dreadful'

Authorities are investigating after a popular Aussie waterway turned a vivid aqua blue colour, with concerned residents worried potential pollutants could kill or injure native fish and birds. The mysterious sight infuriated locals who described it as "a bit of a shocker”.

The striking blue hue of the water at Humpybong Creek in Redcliffe, Moreton Bay near Brisbane, was discovered by a member of the public earlier this week and reported to Queensland Fire and Rescue who attended the scene and tested the water, ultimately finding it to be “benign”.

A spokesperson for Moreton Bay City Council told Yahoo News Australia staff are investigating the unknown substance to discover its origin.

In a post on social media locals described the waterway, also known as Humpybong Billabong, as a "hidden local treasure" and said that most of the aqua liquid seems to be concentrated near a drain area and because there's very little water flow it's "sitting stagnant".

• Locals baffled as popular creek mysteriously turns bright blue

• Calls to ban 'ineffective monsters' used to clean iconic Aussie beaches

• Heartbreaking photo reveals sad trend that poses huge risk to wildlife: 'Mind boggling'

Expert perplexed by 'very strange' discolouration

Water quality expert Professor Stuart Khan, Head of Civil Engineering at the University of Sydney, told Yahoo News the spill was “very strange” and it wasn’t possible to say what it was without chemical analysis.

“There are various microorganisms (bacteria and algae) that can produce some very intense colours in water, including bright greens, pinks and reds,” he said. “But I am not familiar with a microorganism producing this colour.

“It does look like copper contamination, which would be very easy to test for and confirm. In some cases, copper has been used as an algaecide in ponds (to kill nuisance algae), but these pictures would imply very excessive dosing, if it is copper.

“And yes, if it is copper, it’s very toxic to fish and many invertebrate species, so it would have significant ecological impacts.”

Tests to indicate whether pollutants present, says council

A spokesperson for Moreton Bay City Council said there was “no indication of any current impact on wildlife” and the water was due to be tested again for dissolved oxygen levels.

“There has been little dispersion and the spill remains localised,” a spokesperson told Yahoo News Australia.

“The substance has been sampled and is currently being tested. These tests will not be able to identify the exact substance however, the test will indicate if there is any presence of significant pollutants such as any increase in heavy metals.”

The spokesperson said tests can take up to seven days and warned members of the public to avoid contact with the water.

“Officers have inspected the stormwater system in a 400m radius of the impacted area in an attempt to establish a source of the substance,” they added.

Options to disperse it included flushing the system by pumping out contaminated water and disposing of it properly. The Department of Environment, Science and Innovation has also been notified, they added.

Locals furious about state of billabong: 'Doesn't look good'

Fellow Aussies expressed their concerns about the discolouration of the water online.

Many raised concerns about how the local ecosystem would be impacted and hoped that native animals would not be threatened by the spill.

“That’s dreadful. I hope not too many birds or fish were affected,” one wrote.

"That does not look good at all," another said.

Others took a lighter view and suggested it was the result of a baby gender reveal or an attempt to make the creek look like the Whitsundays.

Love Australia's weird and wonderful environment? Get our new newsletter showcasing the week’s best stories.