Relating whirling disease in Yellowstone cutthroat and Tubifex tubifex to environmental gradients

Research on the native Yellowstone cutthroat trout of the Yellowstone Lake basin has provided strong evidence that this subspecies and strain is extremely susceptible to Myxobolus cerebralis, the parasite that causes whirling disease. Up to 20% of all juvenile and adult Yellowstone cutthroat trout within the lake are infected. Sentinel exposure studies (in which uninfected fry are held within cages in a stream and later examined for exposure to whirling disease) suggest that risk of infection is highest in the Yellowstone River and Pelican Creek (the second largest tributary to Yellowstone Lake). Average infection grades in this stream have been 4–5 on the MacConnell-Baldwin scale (0 = no infection to 5 = worst possible infection).