Like storm clouds hanging over the western Montana mountains, the prospect, after a mild, dry El Niño winter, of a warm, dry summer, with diminished stream flows, again threatens the blue ribbon trout streams of southwestern Montana.
That was a common theme among Montana Fish, Wildlife &Parks area fisheries biologists when they made their annual State of the Fishery report to the annual meeting of the George Grant Chapter of Trout Unlimited on April 22, 2010.
Jim Olsen, the biologist in charge of the Big Hole River, reported on the Pennington Bridge stretch of the river, the area from the Pennington Bridge Fishing Access Site, downstream to the river’s confluence with the Beaverhead River to form the Jefferson River. This is an area where the river has been channelized, with riprap on stream banks, and with frequent de-watering in dry years.
In electrofishing surveys, Olsen said he found relatively low numbers of brown trout and rainbow trout, though with the low numbers of fish, there are relatively good growth rates with the fish that are there.
Olson also reported on a study he’d made on mountain whitefish, the first such study in at least 20 years or more. Whitefish, he found, migrate long distances upriver for spawning. Then the fingerlings migrate back downstream where they grow faster in the relatively warmer water of the downstream reaches.
FWP has begun a fish-tagging survey on the Big Hole River. During electrofishing surveys, biologists tagged trout of 12 inches or more last fall. They have placed kiosks at fishing access sites from East Bank to Pennington Bridge where anglers can pick up reporting cards to carry with them on the stream. The tags are placed next to the fish’s dorsal fin, and after a short time in the water get covered with algae. Anglers who catch a tagged fish can wipe off the algae and then record the tag number and other data, such as where the fish was caught, species and size of fish, and drop the card at the kiosk at the end of the outing.
Olsen says FWP hopes to get data on effects of drought conditions, importance of tributaries, migration, and other such information from the tag study.
Jefferson River biologist Ron Spoon reported on some Future Fisheries grant-funded projects on Willow Creek and Parsons Slough, Waterloo-area spring creeks, where FWP has made a number of modifications to the streams to improve rainbow and brown trout spawning and rearing conditions. He reports that the project has dramatically improved fish numbers on that stretch of the Jefferson River.
“It’s the only reason there is a fishery there,” echoed veteran fishing guide Tony Schoonen who frequently works the upper Jefferson River.
Both Spoon and Olsen reported on projects to shift mountain lake stocking from Yellowstone cutthroat trout to westslope cutthroat trout, as westslope trout grow faster. Olsen also reported on an upcoming project on a Big Hole tributary, Cherry Creek, near Melrose, where they will install a fish barrier on the stream and then replace brook trout and rainbow trout with pure westslope cutthroat trout.
Jason Lindstrom reported on the upper Clark Fork River, basically from Butte to Gold Creek. Lindstrom said he’s been trying to find reasons for a steep decline in fish numbers in the Clark Fork downstream from the Warm Springs Ponds. Fish numbers are just a fraction of what they were in 1987, though further downstream, in the Galen area, fish numbers are still consistent with what they were in 1987.
The stream is almost exclusively a brown trout fishery, with some westslope cutthroat trout and, rarely, rainbow trout, which, primarily, came out of the Warm Springs Ponds.
Lindstrom is cautious about pointing fingers at the cause of the decline of fish numbers, saying, “I am still trying to do more work on the issue and get things wrapped up.” On the other hand, he says there has been a decline in water quality on the Warm Springs Ponds, with arsenic levels much higher than in years past. He says, “I can’t prove the fish decline is due to water quality, but my gut says it is.”