Only 2 to 3 percent of the rainbow trout in the Missouri River have severe whirling disease infection, but no one is sure if the levels will stay that low, state wildlife officials reported recently.
That level of infection is far too low to cause the rainbow population to plunge as it did on the Madison River.
George Liknes, fisheries biologist for the Department of Fish, Wildlife and Parks, said the latest tests were on 60 fish.
Whirling disease is blamed for a 90 percent drop in the rainbow population on the Madison.
Unfortunately, the prognosis isn’t so good for Rock Creek, a blue-ribbon tributary of the Clark Fork near Missoula. Recent tests confirm a very serious rate of whirling disease infection in both rainbow and brown trout there.
Between 1992 and 1996, the young rainbow trout numbers have dropped by 78 percent in the middle section of the river. , DataTimes
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