ince then, whirling disease — which targets trout and salmon and causes them to swim in a circular pattern — has been detected in 14 more locations. "Just because of the proximity, there's possibility of birds moving the parasite through ... fish or fecal matter, and also recreational use connecting between the water bodies," said Bill Hunt, the manager of resource conservation with Banff National Park. Hunt said officials are particularly concerned that the disease could eventually infiltrate two more Banff lakes — Minnewanka and Two Jack.