Health Department issue warning after potentially toxic algae discovered in Swan River

The Health Department has issued an urgent warning for people not to eat fish, crabs or shellfish collected from the Swan River after a potentially toxic algae was discovered in the water.

Recent testing has confirmed there are elevated levels of potentially toxic microscopic algae in the Swan River.

Doctors say eating contaminated fish and crabs could result in what is known as paralytic shellfish poisoning.

This can cause nausea, dizziness, numbness of the lips, slurred speech and in severe cases muscular paralysis.

The Health Department note cooking oysters, mussels, clams or fish will not destroy the toxins.

The affected area extends from Pelican Point to Como Jetty and upstream to the Tonkin Highway bridge.

Swimming in those areas is still safe although it should be avoided where there is a red discolouration in the water.

It's unclear what caused the algae to bloom this time or how long it will last.