Killing fish to save frogs

By Ted Williams

By Ted Williams

Shortly after World War II, California fish managers had a brainstorm: They loaded juvenile trout into airplanes and saturation-bombed naturally fishless lakes in the High Sierra Mountains of California. Some of the fish hit rocks and ice, but most hit water.

Gorging on zooplankton, insects and two kinds of mountain yellow-legged frogs, the alien invaders unraveled aquatic and terrestrial ecosystems, often in designated wilderness.

In 2014, the U.S. Fish and Wildlife Service listed both groups of frog as endangered, prompting aggressive action by Sequoia and Kings Canyon National Parks. The agency plan called for eradicating trout in 110 lakes, though trout would remain in 465 park lakes and hundreds of stream miles, leaving plenty of fishing opportunity.

Gillnets would be used where possible. But in 33 lakes, the only option was rotenone, a short-lived, organic fish poison derived from plant roots and applied at 100 parts per billion. In modern fisheries management, rotenone has never been seen to permanently affect a native ecosystem except to restore it. For centuries, Indigenous peoples have used high concentrations to kill fish for consumption. Rotenone only affects gill tissue.

But as early as 2008, numerous anglers, media and local politicians were throwing hissy fits about an effort to protect mountain yellow-legged frogs merely by suspending trout stocking in 175 waters within national forests.

“If the yellow-legged frog disappears, would anyone notice? Seriously. Does anyone really care?” editorialized Feather Publishing in its six newspapers. And Terry Swofford, chair of the Plumas County Board of Supervisors, declared, “To me, this is just another way of destroying our economy.”

When the environmental review process for frog recovery in Sequoia and Kings Canyon National Parks was completed in 2016, it generated plenty of support from environmental and angling communities. But there was still opposition.

Leading the charge against frog recovery via rotenone, and even gillnets, was the environmental group Wilderness Watch. “Poison has no place in wilderness,” it proclaims, wherever rotenone treatments are planned in wilderness.

But the Wilderness Act explicitly provides for the use of poisons to eradicate alien species. Federal permits are routinely issued.

Still, many opponents echoed Wilderness Watch’s false assertion that rotenone is “linked” to Parkinson’s disease. The myth derives from an Emory University study designed to create Parkinson’s-like symptoms, not the disease itself. Concentrated rotenone was pumped into rats’ veins for five weeks. No rat developed the disease, just Parkinson’s-like tremors.

Elsewhere in the Sierra, Wilderness Watch had litigated against, and dangerously delayed, rotenone treatment to save native Paiute cutthroat trout that were being hybridized off the planet by alien rainbow trout. Rotenone, it had testified, might harm mountain yellow-legged frogs — which don’t even exist in Paiute-cutthroat habitat.

After 2016, the opposition fell silent, and in 16 lakes cleared of trout with gillnets, ecosystems reawakened. Before eradication, surveys of two lakes revealed 134 mountain yellow-legged frogs and 53 tadpoles.

Just three years later, there were 4,000 frogs and 14,800 tadpoles.

“Once insects and frogs explode, everything reacts,” said Danny Boiano, the parks’ supervisory ecologist. In all 16 gillnetted lakes, he and aquatic ecologist Laura Van Vranken report spectacular recovery of frogs as well as frog predators such as coyotes, couch’s and mountain garter snakes, and northern water shrews. They’re seeing huge hatches of aquatic insects along with a resurgence of birds.

Ralph Cutter, who runs a guide service and fly-fishing school, understands what’s at stake even though his livelihood depends on the alien trout. His message: “I would much rather leave a legacy of as natural an ecosystem as possible, rather than an artificial and synthetic landscape designed for the amusement of certain enthusiasts — including myself.”

He added that the “Sierra should not be managed like a pee-wee golf course.” And this from the Native Fish Society: “Each high-mountain lake is a beautiful and unique place and is appreciated for what it is. Why treat them like amusement parks?”

Still, some anglers remain ecologically challenged, knifing float tubes and removing and damaging gillnets.

Rotenone use will begin shortly in 33 lakes. “Our first treatments may rekindle angst, so we’ll need to continue with educational efforts,” said ecologist Boiano. With rotenone, there’s always a fight.

Ted Williams, an avid trout angler, is a contributor to Writers on the Range,, an independent nonprofit that seeks to spur lively conversation about the West. He writes about fish and wildlife for national publications.

Yellow-legged frog (Rana muscosa), courtesy USGS

This column was published in the following newspapers:

05/01/2023 Vail Daily Vail CO
05/01/2023 Rock Springs Rocket Miner Rock Springs WY
05/01/2023 Four Points Press Garryowen MT
05/01/2023 Park Record Park City UT
05/01/2023 Sierra Nevada Ally Carson City NV
05/02/2023 Bozeman daily chronicle Bozeman MT
05/03/2023 Lake Powell Chronicle Page AZ
05/04/2023 Wallowa County Chieftain Enterprise OR
05/03/2023 Salt Lake Tribune Salt Lake City UT
05/03/2023 Wenatchee World Wenatchee WA
05/03/2023 Montrose Daily Press Montrose CO
05/04/2023 Taos News Taos NM
05/04/2023 Denver Post Denver CO
05/05/2023 Laramie Boomerang Laramie WY
05/05/2023 St. George Spectrum St. George UT
05/05/2023 Yahoo sunnyvale ca
05/05/2023 Carlsbad Current-Argus Carsbad NM
05/05/2023 Moab Times Independent Moab UT
05/05/2023 Camus-Washougal Post Record Camus WA
05/07/2023 Grand Junction Daily Sentinel Grand Junction CO
05/06/2023 Greeley Tribune Greeley CO
05/11/2023 Wyoming Tribune Eagle Cheyenne WY
05/11/2023 Bandon Western World Bandon OR
05/11/2023 Del Norte Triplicate Crescent City CA
05/11/2023 The Daily Yonder Whitesburg Ky
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Kay Charter
1 year ago

If I hadn’t allowed judicious use of herbicides on my 47 acre bird sanctuary, it would be covered with habitat destroying autumn olive and other nonnative vegetation. The result would be that the more than 40 average nesting species here would find a dearth of insects required to get the birds off the nest.

Matthew Koehler
1 year ago

Wilderness Needs Our Humility and Restraint, Not Our Poisonby Kevin Proescholdt, Wilderness Watch 
Ted Williams’ recent op-ed attacking wilderness advocates like Wilderness Watch for opposing fish poisoning projects in designated Wilderness and incorrectly asserting that we oppose saving mountain yellow-legged frogs contained a number of factual errors, and demonstrated a fundamental misunderstanding of Wilderness and the 1964 Wilderness Act. Readers deserve some corrections.
My friend Ted, who I’ve known since 1996 and admired long before that, is a dedicated conservationist who has done much good through the years. But his zeal to promote fishing and the poison rotenone has seemingly blinded him to the negative implications of fish poisoning projects in designated Wilderness.
First, some of Ted’s factual errors:
• “But the Wilderness Act explicitly provides for the use of poisons to eradicate alien species.” FALSE. There is no such provision in the Wilderness Act. The Wilderness Act does allow some specific exceptions, such as controlling fire, but not the provision that Ted claims.
• Wilderness Watch opposes the use of “even gillnets….” FALSE. While we oppose the use of the poison rotenone in Wilderness, my organization is the leading advocate for using gillnets and other nonmotorized, non-poisonous methods to remove fish from naturally fishless wilderness lakes and streams.
• “Leading the charge against frog recovery…was Wilderness Watch.” FALSE. Wilderness Watch has championed frog recovery, and opposed planting fish in naturally-fishless wilderness lakes BECAUSE those fish consume native frogs, amphibians, and other native biota.
• “Wilderness Watch had litigated against, and dangerously delayed, rotenone treatment to save native Paiute cutthroat trout.” FALSE. Paiute cutthroat trout occupied pretty much all of its very limited native habitat; the project Wilderness Watch and several allies challenged was aimed at establishing a trout population upstream of its native range and in naturally fishless waters in order to create a new angling opportunity. 
Wilderness advocates would like to see imperiled fish saved. But this important work, when proposed in designated Wilderness, must not degrade Wilderness by further damaging natural aquatic ecosystems.
The central focus of the 1964 Wilderness Act is “preserving the wilderness character” of the areas Congress designates. It’s hard to imagine wilderness character being preserved by dumping poisons into wilderness waterways that kill all organisms that use gills—fish, amphibians, and even macroinvertebrates, and then stocking these same waterways with an alien fish predator.
Wilderness is not merely an empty storeroom waiting for humans to fill it with fish because managers place a higher value on fish than native ecosystems. Wilderness is a vibrant ecosystem in its own right that functions without our interference, providing secure habitat for wildlife, fish, and even macroinvertebrates. Wilderness designation allows ecosystems to function naturally without our human interference. Some threatened and endangered species live in Wilderness because these areas often provide their last best habitat, but we shouldn’t jam fish that never before lived there into a Wilderness or into lakes and streams that were historically fishless.
The main descriptor in the Wilderness Act is the word “untrammeled,” and this word actually does appear in the law. It was chosen very carefully by Wilderness Act author Howard Zahniser. Untrammeled doesn’t mean untrampled or untouched, as some assume, but it means unmanipulated, unconfined, or unhindered. After designation, Wilderness must be allowed to evolve on its own terms without our manipulations, even if humans had damaged the landscape in the past or manipulated its ecosystem previously.
The Wilderness Act thus requires us to stop imposing our human desires or whims on wilderness landscapes, and to allow Wilderness to function without our manipulations and interferences. At a time when humans are putting our planet in peril, Wilderness needs and deserves our humility and restraint, not our poisons.

Kevin Proescholdt is the conservation director for Wilderness Watch, a national wilderness conservation organization headquartered in Montana. He has worked on wilderness conservation for nearly 50 years.

Dave Marston
1 year ago

From Ted Williams in response to the above letter:

I was distressed to read the commentary of my old friend and colleague Kevin Proescholdt of Wilderness Watch wrongly alleging “factual errors” in my May 4th op-ed defending the National Park Service’s effort to save endangered mountain yellow-legged frogs by poisoning and gillnetting a small percentage of the alien trout that prey on them.
One might suppose that a group with the name Wilderness Watch would understand the Wilderness Act which does indeed provide for pesticides to preserve wilderness assets like native fish and wildlife: “Nothing in this Act shall be construed as affecting the jurisdiction or responsibilities of the several States with respect to wildlife and fish in the national forests.” Federal permits for pesticide use are routinely issued.
Proescholdt proclaims that Wilderness Watch doesn’t oppose the use of gillnets to remove alien trout, but the public comments from his organization in the Park Service’s environmental review prove otherwise.
The Forest Service, Fish and Wildlife Service and California Fish and Wildlife used rotenone to save the Paiute cutthroat trout from being hybridized off the planet by alien rainbow trout. But litigation from Wilderness Watch delayed the project for years, nearly ushering the rarest salmonid in America into extinction.
Proescholdt’s claim that rotenone “kills all organisms that use gills — fish, amphibians, and even macroinvertebrates” and that “these same waterways are then stocked with alien fish predator” is patently false. Amphibian adults are unaffected by rotenone, and rotenone is applied after larvae have metamorphosed. The vast majority of macroinvertebrates survive by a process called “catastrophic drift.” They sense rotenone, dislodge, and go downstream. The few that succumb are rapidly replaced, and populations generally do better because they aren’t eaten by alien fish. Finally, the fish stocked are imperiled natives, not “alien fish predators.”
Most distressing is Wilderness Watch’s notion that projects to save icons of wilderness like the federally threatened Paiute cutthroat trout are motivated, in Proescholdt’s words, by “a zeal to promote fishing.” Wilderness Watch imagines that Trout Unlimited volunteers hike 14 miles into the high Sierra to catch seven-inch Paiute cutthroat. Throughout the West, Wilderness Watch opposes, impedes and sometimes blocks rotenone projects. It can’t conceive that native-fish recovery could be about anything other than sport. This is how it dismisses Gila trout recovery, also mandated by the Endangered Species Act: “It is both sad and ironic that it was Aldo Leopold who convinced the Forest Service to protect the Gila [National Forest] as our nation’s first wilderness in the 1930s—now, it is in danger of being converted to a fish farm for recreationists.” I wish my friend Kevin Proescholdt and Wilderness Watch would realize that fish are wildlife, too.
–Ted Williams

Ted Williams
7 months ago
Reply to  Dave Marston

Another Point:

Proeschold writes: “Paiute cutthroat trout occupied pretty much all of its very limited native habitat; the project Wilderness Watch and several allies challenged was aimed at establishing a trout population upstream of its native range and in naturally fishless waters in order to create a new angling opportunity.” False. Paiute cutthroat trout occupied none of their native habitat. They were eliminated by alien rainbow trout. Rotenone treatments restored them to their native habitat. The pure Paiute population upstream was already established, and that establishment had nothing to do with “angling opportunity.” It had everything to do with saving this threatened species from extinction as mandated by the Endangered Species Act.

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