Fish Die-off at Buffalo Pound Lake, Saskatchewan
On June 8th, 2012, the Western and Northern regional office of the Canadian Cooperative Wildlife Health Center received reports that large numbers of yellow perch (Perca flavacens) were washing up dead at Buffalo Pound, a small eutrophic lake located approximately 50-km north of Moose Jaw, Saskatchewan. A team immediately responded by visiting the lake to determine the extent of the die-off and to collect diagnostic samples. It is estimated that this die-off involved tens of thousands of yellow perch. Necropsies and bacterial cultures indicate that these fish were suffering from a bacterial infection that caused severe tissue destruction (particularly involving the skin, muscles, and gills), which is likely consistent with columnaris disease, a bacterial disease caused by Flavobacterium columnare. This pathogen occurs in freshwater fish worldwide, and has been frequently identified as a cause of mortality in both wild and farmed fish. Attempts are currently being made to confirm its identity, and to determine predisposing factors that may have played a role in yellow perch becoming susceptible to this particular pathogen.
Although this die-off lasted approximately one week, CCWHC Western Northern continues to monitor Buffalo Pound Lake, as well as Blackstrap Lake, for evidence of mortality in an attempt to better understand fish die-offs in Saskatchewan lakes.