Popular Johnson Lake in Banff, closed by Parks Canada for stated fish management purposes last week, has now been confirmed as having been affected by Whirling Disease.
On Tuesday (Aug. 23), the Canadian Food Inspection Agency (CFIA) confirmed whirling disease, a fish disease that affects salmonoids, in the lake.
While awaiting laboratory test results, Parks Canada implemented an area closure for Johnson Lake on Aug. 18 in an effort to reduce potential spread of the disease. The closure included two shoreline beach areas, the marsh flowing into the lake and outlet flows. Swimming, paddling, boating and fishing were prohibited during the closure.
At the time, Parks stated the closure was for fish management, adding more information would be made available as appropriate.
Upon initial notification of the suspected case of whirling disease, Alberta formed a response team consisting of biologists, hydrologists and emergency response personnel to ensure that detection of the disease is met with a swift and co-ordinated response.
According to a CFIA press release, the disease is not harmful to humans, but can have a significant impact on some fish populations. It can be transmitted to other water bodies through gear and equipment used for swimming, paddling, boating and fishing.
Alberta Environment and Parks has taken approximately 700 samples from waterbodies downstream of Banff National Park since Aug. 13 and sent them to a testing facility. This is in addition to ongoing testing by the Canadian Food Inspection Agency. Results are expected in early September.
Whirling disease has been observed in the United States since the 1950s and is prevalent in the western and northeastern states.
According to CFIA, Whirling Disease effects vary between fish species and different water bodies. Rainbow and Westslope cutthroat trout, salmon and whitefish are most susceptible to the disease.
Affected fish may exhibit a whirling swimming pattern, skeletal deformities of the body or head, for example, shortening of the mandible and indentations on the top of the head and the tail may appear dark or even black.
