Battling The Disease

Fish management

The U.S. Senate Environment and Public Works Committee met in Bozeman, Mont., recently to hear about the disease that threatens to devastate Montana’s wild rainbow trout populations.

Sen. Max Baucus, the committee’s highest-ranking Democrat, said the hearing was “a great opportunity to discuss whirling disease, Montana’s response to this challenge and the future federal involvement possible to protect and enhance Montana’s native fisheries.”

Whirling disease has been found in several drainages and has been blamed for the extensive loss of rainbow trout in the Madison River.

Results from a survey conducted this summer showed that rainbow trout catch rates on the upper Madison declined 70 percent when compared to catch rates in 1981. Anglers this summer averaged five hours of fishing to catch one rainbow. In 1981, anglers fished for about 90 minutes to catch a rainbow.

Whirling disease is caused by a parasite that deforms the cartilage of young rainbows, causing them to swim in a “whirling” pattern making it difficult to feed or avoid predators. Brown trout are not affected.

, DataTimes