Department of Health warns against eating fish, crabs, shellfish from Swan and Canning Rivers due to toxic algal bloom

A toxic algal bloom affecting the Swan River since December has spread and has now been detected as far upstream as Middle Swan Bridge.

The Department of Health is warning people not to consume fish, crabs or shellfish collected from within the Swan and Canning river systems due to the algal bloom and the potential for increased toxin levels.

Toxin testing in December and mid-January confirmed that some mussel samples collected in the affected area exceeded the comparable food safety guideline level.

Crabs tested did not exceed this level but higher concentrations in both the Swan and Canning rivers over the last month are likely to result in increasing toxin levels.

Additional testing is under way to better determine how this alga affects fish, crabs and shellfish.

The ingestion of toxins produced by this microscopic species of algae can produce a type of poisoning known as paralytic shellfish poisoning which can cause muscular paralysis.

Cooking does not destroy these toxins.

The public is also advised to avoid swimming in areas where the water is discoloured.