Canning River: Scientist explains reason behind toxic blue-green algae as swimmers warned by council

The Department of Health has issued a warning for parts of the Canning River in which blue-green algae is growing that is potentially a health risk to both residents and pets.

The City of Canning has put up warning signs at the main entry points of Kent Street Weir and Mason’s Landing Park with water users advised to avoid swimming, wading, kayaking, fishing and other recreational activities until the water has cleared.

In a statement, the City of Canning said “as a general rule, people should avoid water that has surface scum, is discoloured, murky, or smells unpleasant”.

Dalcon Environmental principal scientist Stuart Helleren said most of Perth’s wetlands would be affected by this type of algae at some point throughout the year.

“The primary cause of this algae is generally nutrients,” Dr Helleren said.

“But also the warm weather, this is generally a seasonal event.”

Dr Helleren said the primary concern of this algal bloom was if it comes into direct contact with people or pets.

“Dogs can succumb to toxins quite quickly if they consume it,” he said.

“These algae can produce allergic type reactions on skin through direct or indirect contact”.

According to the Department of Health, risks from contact with the algal blooms include skin rashes, eye irritation, swollen lips or gastroenteritis.

The Department of Biodiversity, Conservation and Attractions will continue monitoring the algal bloom and provide further advice to the Department of Health.