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Looking out for bull trout.

Byline: MIKE STAHLBERG The Register-Guard

CHAD HELMS' eco-challenge involves wading in waist-deep mud, fighting through dense undergrowth and picking his way along a steep, slippery stream full of frothing whitewater.

Although it may look like it at times, Helms is not entered in one of those grueling cross-country races made popular by "reality" television.

His challenge is to help save a small, isolated population of bull trout clinging to existence in the South Fork Willamette River above Cougar Dam.

About 60 adult bull trout are believed to live in the watershed, spawning in the icy waters of Roaring River, which cascades off the slopes of Chuksney Mountain and into the South Fork of the McKenzie River about 50 miles east of Eugene.

Helms is one of three Oregon Department of Fish and Wildlife employees working on a $200,000 anual contract from the Army Corps of Engineers.

Their assignment is to monitor the bull trout and to minimize the threat posed to the fish by construction of new temperature control facilities at Cougar Dam.

The federal government is going to such expensive lengths over so few fish because the Columbia River strain of bull trout is listed as threatened under the federal Endangered Species Act. And scientists have classified the South Fork McKenzie population as facing a high risk of extinction.

Baby-sitting the bull trout has required a mixture of dirty grunt work and high-tech wizardry.

The dirty part of the job hit a low point last spring when Helms and project leader Mark Wade struggled through soft, thigh-deep mud to check isolated pools of water left behind by the draw-down of Cougar Dam. They were looking for any bull trout that might have been stranded in the pools.

They found three 13- to 15-inch bull trout in one pool in an old submerged rock quarry. Two of those fish were moved safely to the river, but the third had been injured by the net and died.

Now that the mud has dried, Wade is working with the Corps of Engineers to cut channels through the banks of the pools so more trout aren't stranded as the reservoir level rises and drops during the coming winter.

"We want to get that pool drained so we don't have the same problem next year," Wade said.

Meanwhile, the most dangerous part of the job, Helms says, has been conducting the spawning surveys on a 1.8-mile long section of Roaring River, the only place in the South Fork watershed where bull trout have been found to spawn.

Biologists were stunned to find the fish spawning on a stream with such a steep gradient.

"It's pretty amazing - in fact, it's totally amazing where they spawn," Wade said.

Last fall, Wade's crew counted 34 bull trout redds, or gravel nests, tucked in open spots between the whitewater on Roaring River. That's the highest redd count in nine years.

This year's spawning surveys are scheduled to begin next week.

The bull trout population has been growing in recent years, Wade says, due to two factors. First, the state has been trucking spring chinook salmon above the dam and allowing them to spawn in the South Fork, thus increasing the supply of juvenile salmon, which bull trout feed upon.

In addition to counting redds by hand, the bull trout team uses technology to count fish as they move up and down Roaring River, and to track the movements of marked fish in the reservoir and in the river.

The machine count is accomplished with the use of a "Vaki Riverwatcher," an elaborate and expensive piece of equipment Wade borrowed from other researchers. The Riverwatcher takes a photo of anything over a certain size that breaks infrared beams shooting through a 16-by-20-inch opening. Migrating fish are funneled through the opening by a system of weirs.

"Every time a fish comes through, it takes a picture," Wade said. "That allows us to confirm it was a fish, and not an otter or a stick."

In the 2001 spawning season, the Riverwatcher counted 66 fish longer than 12 inches moving upstream and 66 moving downstream. Bull trout quickly return to their main feeding areas after spawning.

When Helms checked it Tuesday, the Riverwatcher indicated 18 fish had passed upstream through the small opening so far this season.

"They're starting to move," he said.

Wade will be closely watching the redd counts and Riverwatcher tallies this month, looking for any sign of a drop in the adult population. That could be a sign of bull trout mortality associated with the draw-down in the reservoir.

Meanwhile, the bull trout watchers are also using two electronic systems of tracking fish movement. Radio telemetry is used to track the movements of adult bull trout. Tiny transmitters have been surgically implanted in 21 adults captured in nets or "screw traps," or by angling. Helms uses radio antennas weekly to check on the location of the fish.

The movement of juvenile bull trout is being monitored by the use of "passive integrated transponders," or PIT tags. Young bull trout migrating downstream from Roaring River to the South Fork McKenzie are captured in a rotary fish trap. Then a match-stick-sized PIT tag is inserted in a small incision made in the fish's stomach.

The tag, which is individually numbered, can be picked up by "swim-through antennas" that have been installed near the mouth of Roaring River, on the South Fork near Dutch Oven campground below Cougar Dam.

The technology is similar to that many companies use for employee identification cards that can be used to unlock doors. The antenna will detect a PIT fish that passes within about five feet. So far no bull trout PIT tags have been picked up by the antenna below the dam, an indication that fish so far are not leaving the reservoir via the diversion tunnel.

Knowing as much as possible about the movement of the bull trout is important in case it becomes necessary to capture them and move them elsewhere for safe-keeping.

"If things start going bad above the reservoir and bull trout start dying for some reason - like going through the dam - what we may do is capture them next year and move them down below the dam," Wade said.

CAPTION(S):

MIKE STAHLBERG / The Register-Guard Chad Helms checks a rotary fish trap used to capture bull trout on their migration downstream on the Roaring River toward Cougar Dam. Chad Helms (right) and Mark Wade worked to save bull trout stranded in pools when Cougar Reservoir was drained last year. MIKE STAHLBERG / The Register-Guard ODFW employee Chad Helms is monitoring bull trout in the South Fork Willamette River in an attempt to minimize the threat posed by construction of new temperature control facilities at Cougar Dam. Oregon Department of Fish & Wildlife A "passive integrated transponder" radio tag is inserted into a bull trout to allow researchers to monitor the fish's movement.
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Title Annotation:Biologists go to great lengths to save endangered fish in South Fork McKenzie; Recreation
Publication:The Register-Guard (Eugene, OR)
Date:Sep 5, 2002
Words:1154
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Next Article:`Gravel Popsicles' aid researchers in river studies.


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