Reclaiming upper Hermosa Creek
DOW preps for native cutthroat reintroduction

SideStory: Forest Service to restore banks, habitat

Two anglers tie one on in hopes of landing some trout on Upper Hermosa Creek last summer. The DOW is embarking on a native Colorado River cutthroat recvoery plan this summer, which would remove non-native brown, brook and rainbows and restore cutthroats to 4 miles of stream, from Hotel Draw to the headwaters./Photo by Steve Eginoire

by Missy Votel

The beleaguered Colorado River cutthroat trout is getting a new lifeline this summer. Thanks to a joint effort between the Colorado Division of Wildlife and the U.S. Forest Service, the native fish, once close to landing on the endangered species list, will be given an exclusive home in upper Hermosa Creek.

Later this summer, the DOW plans to remove nonnative trout, such as brown, brook and rainbow, from a 4-mile stretch of the waterway from Hotel Draw to the headwaters, and replace them with Colorado cutthroats.

“Hermosa Creek has fantastic attributes that make it an excellent place for the recovery,” said Jim White, aquatic biologist with the Durango DOW. Aside from excellent water quality, which helps trout grow well, the Hermosa has a series of natural waterfalls that act as barriers between the native and nonnative fisheries. Furthermore, it is on public land, thus streamlining the recovery process.

White said this summer’s recovery effort is phase one in a two to three phase plan to bring Colorado cutthroats back to the Upper Hermosa drainage. “The overall goal is to link the Upper Hermosa with the East Fork, making for one big cutthroat population,” said White. “This gives us an opportunity to restore 20 miles of habitat.”

The advantage of such a “metapopulation” is that outbreaks in disease won’t wipe out the entire population, as sometimes happens on smaller creeks.

One of only three species of cutthroats native to Colorado, Colorado River cutthroat historically occupied portions of the Colorado River drainage in Wyoming, Colorado, Utah, Arizona and New Mexico. However, in the mid-1800s humans began settling the West, and the fish were over-harvested. Non-native salmonids (brook, brown and rainbow trout) were introduced as an alternative and soon outcompeted the natives. Today, only a few pockets of cutthroats remain, primarily in isolated headwaters and lakes. According to White, the fish now occupy a mere 13 percent of their historic range.

Colorado River cutthroat are recognized as a “species of special concern,” and significant resources have been dedicated to their conservation. In 1994, a consortium of state fish and wildlife agencies recognized the need for action, and directed Colorado, Utah and Wyoming to develop a conservation plan. The result was 2006’s Conservation Agreement for Colorado River Cutthroat, a collaborative framework for conservation of the cutthroat which helped prevent the fish’s listing as endangered.

However, long before this agreement was reached, local agencies were working on preserving Colorado cutthroats in the San Juans. In 1992, a hold-out population of pure Colorado River cutthroat trout was discovered in a remote stream within the Weminuche Wilderness. The DOW then identified the East Fork of Hermosa Creek, located near Purgatory, as an ideal stream to reintroduce the natives. Nearly two decades later, that population is flourishing.

“In 1990, that was a brook trout stream. We started reclamation and by 1992, it was pure Colorado cutthroat down to the Sig Creek campground,” said White.

While the effort to re-establish the native cutthroats in the Hermosa drainage has many supporters, including members of Trout Unlimited, it is not without detractors. “We’ve heard some grumbling,” said White. “There are anglers out there who like not knowing what’s on the end of their line.”

In addition, the reclamation effort will entail some down time for anglers as the nonnative fish are removed and the new fish are stocked. Furthermore, the newly stocked fishery may be subject to catch and release rules, which are also in effect on the East Fork, to protect from over-fishing.

To put it politely, cutthroats are widely regarded as among the less sharp trout in the stream. “That’s the primary reason we changed to catch and release – because they are so susceptible to overharvesting,” said White.

Another concern with the reintroduction is the displacement of the resident beaver population. White said that unfortunately, beaver dams will have to be taken down and the beavers trapped and relocated. However, he stressed that the relocation will be temporary. “We love beavers, don’t get me wrong,” said White. “They are a keystone species and good for the riparian ecosystem. But you can’t restore trout with dams, and as we all know, beavers can be tenacious little buggers.”

White said there is a large, intact population of beavers upstream, and he expects the animals to quickly repopulate the area. Furthermore, he added that some of the dams on the stretch may already be abandoned. “Not every pond has an active beaver, but we’ll verify first.”

Perhaps the biggest downside to the recovery effort is the actual removal of the nonnative trout. White said the chemical rotenone, which has been used for the last 80 years and was applied in the East Fork, will be used. Although not particularly toxic to mammals, rotenone – a naturally occurring compound from the roots of certain species of beans– is toxic to gill-breathing animals. Also used as an organic insecticide for roses, rotenone breaks down quickly in the environment.

“The hardest thing for us is the use of chemicals,” said White. “But any time (natives and nonatives) are mixed, the cutthroats don’t persist. That’s why we have to take these draconian measures. Hence the word, ‘reclamation.’”

Several precautions will be put in place to ensure that the treated water does not flow into the lower stretches of the Hermosa, White said, adding that the whole process will take about 2 hours from start to finish. “Dilution is the solution,” he said.

White said there is interest from Trout Unlimited members to relocate as many fish beforehand as they can. He also said prior to the application, the public will be invited to harvest from the stretch. “There’s a lot of community interest in doing that, and we’re happy to accommodate.”

Overall, White said the public has been in favor of the reclamation, including the Forest Service and the Upper Hermosa Working Group.

Buck Skillen, a local TU member, said although the group’s board of directors has not taken an official stance on the Hermosa plan, in general TU is supportive of bringing back natives. Although he said some members of the local angling community would rather not see the stream “messed with,” many others agree with restoring the natural balance. “As for me, personally, I am very in favor of the reintroduction,” he said. “Bringing back natives is very important. We try to support the DOW and the Forest Service as much as we can.”

In the meantime, White asked for the public’s patience with the project, which was originally slated for 2008 but postponed when a stream barrier broke. He added that another treatment may be needed in 2012 as well. “These things just take time, they are very complex,” he said. “But the biggest word is ‘temporary.’ It still might take several years, but it will be temporary.” •