Six more locations have been added to the list of rivers, creeks and lakes with confirmed cases of whirling disease in Banff National Park.
Whirling disease doesn’t harm people or other mammals, but can have a significant effect on salmonoids—salmon, trout, char and whitefish.
It’s caused by a microscopic parasite that penetrates the head and spine and eventually causes the fish to swim erratically — or whirl. That leads to difficulty feeding and avoiding predators.
The disease was initially found in Banff National Park’s Johnson Lake at the end of August.
Less than three weeks later, officials announced it had spread to the upper Bow River, downstream from the confluence of the Bow and Cascade rivers.
On Monday, the Canadian Food Inspection Agency added six more locations to the list:
- Spray River (upstream from the confluence of the Bow River and Spray River)
- Cascade Creek (upstream from the confluence of the Cascade River and Cascade Creek)
- Carrot Creek (upstream from the confluence of the Cascade River and Carrot Creek)
- Bow River (near Tunnel Mountain)
- Lower Cascade River (upstream from the confluence of the Bow River and Cascade River)
- Bow River (downstream from the confluence of the Bow River and Carrot Creek)
The additional detections aren’t necessarily an indication the disease is spreading, the CFIA said in a note on their website.
“Whirling disease may have been present for several years and the ongoing sampling will help determine the extent of the distribution and the most appropriate disease response.”
Whirling disease has been found in the United States since the 1950s. Alberta Environment and Parks said it is prevalent in the western and northeastern states.