Sydney Harbour mysteriously turns blood red – as cause of shock change is revealed

A section of Sydney Harbor has turned blood red to the alarm of residents and visitors, with a council offering the likely explanation.

The red tide was seen on Monday afternoon at the harbor waterfront at Milson Park in Kirribilli, adjacent to the Sydney Harbor Bridge on Sydney’s lower north shore.

Curious visitors to the popular harborside park followed the flow of red water back to a stormwater drain.

A North Sydney Council spokeswoman told Daily Mail Australia the likely cause of the color change is plumber’s paint.

“The council is aware of the red tide flowing into the harbor from Milson Park and officers have investigated but have been unable to locate the source,” she said.

“We have reported it to the EPA (the NSW Environment Protection Authority).”

The substance, also called fluorescein, is non-toxic and odorless.

Plumbing paint is used to locate the precise point of leakage in pipes, pipes and drains.

Bright red water was seen entering parts of the harbor front of Milson Park in Kirribilli on Monday afternoon

It is recommended to keep the use of the substance to a minimum to prevent these types of problems from occurring Monday when it enters natural waterways.

A spokesperson for NSW EPA confirmed the council had alerted the agency to the presence of the dye in the drain.

The latest incident comes just months after the water in the bay near Hipwood Street turned fluorescent green on September 25.

The mysterious green substance was spotted flowing from a storm drain.

Authorities determined that this was also caused by plumber’s paint.

No hazards to marine life or surrounding properties have been identified.