Remember to clean your Swan and Canning River crab

News story
Perth locals are reminded to use caution when crabbing in the Swan and Canning Rivers due to the potential for the harmful alga Alexandrium.
blue swimmer crab on a bowl of ice

Algae Alexandrium can produce Paralytic Shellfish Toxins which can accumulate in crustaceans and mussels.  Eating affected blue swimmer crabs and mussels may be dangerous and, in extreme cases, can cause death.

It is recommended that fishers remove the head, guts (mustard) and gills from blue swimmer crabs caught in the Swan and Canning rivers before freezing, cooking or eating them. 

Cooking whole crabs could potentially spread the toxin from crab guts into the flesh or broth. Freezing crabs with guts still in place could result in the toxin spreading to the flesh during thawing.

If you become ill after consuming crabs or mussels seek medical attention promptly.

River users should stay aware and look out for signs near the rivers or Alexandrium updates in the media and outdoor/fishing tackle stores.

And remember - you still have to land and transport blue swimmers home as whole crabs, unless you plan to eat them immediately.

Watch a video on how to properly clean blue swimmer crabs. 

More information is available from the Department of Primary Industries and Regional Development at or

Page reviewed 14 January 2022