The Department of Health continues to advise people not to eat fish, crabs or shellfish collected from within the Swan River, extending from Pelican Point to Como Jetty and upstream to Tonkin Highway Bridge. This area includes the commonly known areas of Matilda Bay, Perth Waters, Elizabeth Quay, Barrack Street Jetty, Claisebrook Cove, Maylands Yacht Club, Ascot Waters and Riverside Gardens.
Recent water testing has shown a decline in the level of potentially toxic Alexandrium algae but testing of mussel and crabs has detected the toxin so the existing warning remains in place.
The ingestion of toxins produced by this microscopic species of algae can produce a type of poisoning known as paralytic shellfish poisoning (PSP).
It is important to note that cooking will not destroy these toxins.
People who consume wild shellfish, crabs or fish collected from the affected area of the Swan River may experience symptoms including:
- tingling or numbness of the lips
- prickliness of the fingertips and toes
- nausea or vomiting
- impaired balance
- slurred speech
- double vision
- difficulty in swallowing or breathing,
- loss of fluids and diarrhoea.
In severe cases PSP may cause muscular paralysis in people who consume affected shellfish, crabs or fish.
Anyone who has consumed shellfish, crabs or fish collected from the affected area of the Swan River and experiences any of these symptoms should seek urgent medical attention, particularly if they have difficulty breathing.
They should also retain uneaten portions of mussels or other shellfish because these may assist with determining a likely cause of any symptoms.
Shellfish includes oysters, mussels, clams, pipis, scallops, cockles and razor clams.
As a general rule people should avoid eating recreationally collected shellfish in rivers, estuaries or other waterways where there is an increased likelihood of contaminant or nutrient inputs that could lead to increased microscopic algae growth.
Farmed shellfish purchased in supermarkets and other commercial outlets in WA are not affected because there is a strict quality-assurance program to ensure they are safe for human consumption.
Other recreational activities including swimming, skiing and boating in the Swan River are not affected by this microalgae species, but as a general rule swimming should be avoided in areas of discoloured water.”
Health warning signs advising against crabbing, shellfish collection and fishing have been erected at key locations including jetties, boat ramps and key accessible foreshore areas within the affected region.
The Department of Biodiversity, Conservation and Attractions will continue to monitor algae levels within the Swan River and will resample mussels and crabs for toxins in the next two weeks.
Not all waterways are monitored for algal blooms and anyone who sees or suspects an algal bloom in a waterway should report this to the Department of Water and Environmental Regulation’s ALGALWATCH during office hours on 6250 8064 or to the relevant local government authority for assessment.