The Department of Health is warning members of the public to avoid areas of the Swan River where dead fish are visible and not to collect dead fish. Fishing in the area, as well as direct contact with the water, is also not advised.
The warning follows advice from the Parks and Wildlife Service at the Department of Biodiversity, Conservation and Attractions (DBCA) that at least 600 dead fish have been reported in the Swan River.
The fish, mostly bream, have been reported near Garratt Road Bridge in Bayswater and upstream, however the extent of the fish kill is still being investigated.
Significant rainfall and increased flows from the Avon River may have contributed to the fish kill.
An increased amount of debris is also expected to float downstream in coming weeks following the large rainfall event.
While DBCA will continue to investigate the cause of the fish deaths, information from members of the public is also welcome. Anyone who sees dead or sluggish fish in other areas in the Swan Canning Riverpark are asked to report this to FishWatch on 1800 815 507.