Montana’s Trout Streamsflooded With Problemst

These are hard times for Montana’s Blue Ribbon trout streams.

A microscopic parasite has decimated trout populations in the great Madison River and is killing trout in other Blue Ribbon rivers.

Bucket biologists, by surreptitiously dumping pike in lakes along the upper Blackfoot River drainage, have brought about a disastrous drop in trout populations in the lakes.

The Yellowstone River flooded early this year and wiped out Anderson and DuPuys spring creeks, the best known fly fishing spring creeks in the world.

A growing population of mackinaw trout in Yellowstone lake is threatening the future of the cutthroat trout in the lake and the Yellowstone River.

And late winter flooding behind Milltown Dam just east of Missoula flushed deadly metals into the Clark Fork River.

The Clark Fork, from just above Missoula to several miles below St. Regis, is a trout fisher’s dream stream. To hundreds of Washington and North Idaho fly fishers, its next to living in heaven.

Fisheries biologists know that the metals flushed into the Clark Fork killed most of the trout and probably insects in a 2.3-mile stretch below Milltown Dam. What they don’t know yet is whether enough of the suspended metals rode the flood water down through St. Regis to kill thousands of rainbows and brown trout.

The biologists will put their electro-fishing probes into the water in the Superior and St. Regis areas in September and October, according to Bill Thomas, information officer for the Missoula office of Montana’s Fish, Wildlife and Parks Department.

“We’ve got a lot of data on trout populations in those areas, he said. “We can compare the trout populations in the Superior and St. Regis areas with the trout populations for each of several past years.

When floods forced the opening of the flood gate of the Milltown Dam last February, zinc, copper and arsenic were flushed into the Clark Fork. Samples taken in the Milltown section of the Clark Fork showed 630 to 770 parts of copper per billion; zinc, 1,140 to 1,310 parts per billion, and arsenic, 97 parts. The state standard, intended to protect aquatic life, is 18 parts per billion.

Biologists Dennis Workman and Rod Berg learned, by electro-fishing a 2.3-mile-long section of the Clark Fork River below Milltown Dam, that the number of catchable-size rainbows dropped 62 percent from last year’s number and the brown trout population plunged 56 percent.

The trout that survived in the Milltown section were in poor shape. They were skinny and lethargic.

Juvenile trout losses were even greater, a 71-percent drop for rainbows and 86 percent for brown trout.

The biologists ruled out the whirling disease, drought, angler harvest and ice-scoring as the causes of the trout kill.

Thomas said biologists don’t know how quickly the metals settled in the Clark Fork below Milltown Dam. “They won’t even speculate, he added.

By electro-fishing in the Superior and St. Regis areas, the biologists may be able to determine whether the metals drifted with the flood water for many miles below Milltown Dam. If enough of the metals were washed with the current down through St. Regis, trout fishing could be poor the next few years.

Fly shop operators, who make a lot of money guiding anglers, are saying that they think the metals settled quickly. They contend that their clients are catching as many fish this year as last and that the trout are in good condition.

Inasmuch as the Clark Fork is one of the four most important trout streams in the Missoula area and the fly shop operators take clients down the stream nearly every day, they almost certainly don’t want to discourage would-be clients from fishing the river. However, they could be right.

Some fly fishers, including several in the Spokane area, believe there are still good numbers of large rainbows and browns in the river below Superior. A few believe the population has dropped. So, who is to be believed?

The biologists, who have the equipment to evaluate fish populations, will come up with answers some time late this fall.

Fly fishers, more than any other anglers, will be hoping that the biologists will report that they found trout populations in the Superior and St. Regis areas are as big and healthy as they’ve been the last few years.

The Clark Fork is only a 2-hour drive from Spokane. Many fly fishers drive to St. Regis over Interstate 90 and arrive in plenty of time to fish the hatches. They float the river 5 to 6 hours and are back in their homes in time for dinner. If the fish kill extended below Superior, they would lose a first-class trout stream for a few years.

, DataTimes