Whirling disease affects fish by causing appearance changes and a whirling swimming pattern, and has been found in the Bow River within Banff National Park.

The Canadian Food Inspection Agency has quarantined all commercial fish culture operations and has stopped stocking fish until the disease clears. Testing is being conducted on the Bow River, Oldman River and upper Red Deer River watersheds.

Whirling disease is harmless to humans, but can spread quickly in fish populations. Anglers, boaters and recreational water users can help stop the spread of the disease by:

  • Not moving live or dead fish from one body of water to another
  • Cleaning boats and equipment after use
  • Drying all equipment thoroughly before transporting
  • Washing and drying dogs that have swum in the river

You can spot whirling disease by looking for these symptoms in fish:

  • A whirling swimming pattern
  • A bent body caused by spinal deformities
  • A black or dark-coloured tail

The types of fish most commonly affected are rainbow, westslope cutthroat and brook trout, some salmon and mountain whitefish.

If you suspect a case of whirling disease, call 1-855-336-BOAT (2628).