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Government of Western Australia - Department of Fisheries
The warning remains in place
Thursday 9 April 2020

Update – Warning remains in place not to consume wild shellfish, or fish, from SWAN-CANNING algal bloom impact zone

The Department of Health’s algal bloom warning for the Swan and Canning river systems issued on 22 February is still in place.

Large areas of the riverpark are impacted the map here shows the Alexandrium bloom's extensive spread, so people are advised not to consume wild shellfish (including crabs) or fish from the impacted zone.

The ingestion of toxins produced by this alga through eating crabs, other wild shellfish, or fish from the zone can produce a type of poisoning known as paralytic shellfish poisoning, which cooking does not destroy.

Although concentration in both rivers has decreased over the last month, testing of mussels collected from within the affected areas show toxin concentrations remain above food safety guideline levels. This warning is likely to stay in place until at least May 2020.

For more details, see the Department of Health warning:

Read detailed FAQs on the Alexandrium algal bloom and paralytic shellfish poisoning (external site).

Further information is available at



Last modified: 9/04/2020 3:49 PM

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