"Monster" Lahontan cutthroat trout swimming one step closer to native spawning home

By Dan Hottle
April 20, 2016

An angler holds a freshly-caught Pilot Peak Lahontan cutthroat trout at Pyramid Lake. Courtesy photo by Greg Ritland for USFWS

A welcomed increase in precipitation throughout the drought-weary Sierra Nevada range this spring combined with a growing understanding of the reproductive habits of one of the most unique species of inland trout to ever be brought back from the brink of extinction has both anglers and biologists alike very enthusiastic.

Improved water flows in the Truckee River between Lake Tahoe and Pyramid Lake are enabling the migrating Pilot Peak strain of Lahontan cutthroat trout (LCT) to travel farther upstream to spawn in their native habitat than the fish have been able to do on their own in nearly a century.

Derek Bloomquist (left), FWS fisheries biologist, assists
Michelle Moore (in hat) and other members of the Pyramid
Lake Paiute tribal fisheries program during trout spawning
operations at the Lahontan National Fish Hatchery Complex
in Gardnerville, Nev. Photo Credit: Dan Hottle/USFWS

For more than 20 years, biologists from the U.S. Fish and Wildlife Service’s Lahontan National Fish Hatchery Complex and partnering Pyramid Lake Paiute Tribe have worked to restore these unique fish to Pyramid Lake and the Truckee Basin. This season’s river conditions are providing valuable research opportunities for Complex staff to study the species’ behavior in an improved, in-stream spawning habitat and better focus their collective management of this newly-established reproductive population.

“From the outset of the program, our goal has been to link the health and connectivity of the Truckee River watershed with the wild native population of Pilot Peak LCT in Pyramid Lake,” said Lisa Heki, project leader for the Lahontan National Fish Hatchery Complex, south of Gardnerville, Nevada. “Helping the species migrate the full length of their historic range more than 120 miles from Pyramid to Lake Tahoe is our ultimate goal, and would be the culmination of more than 20 years of restoration work.”

Since 1995 the Complex has reared a wild broodstock of Pilot Peak LCT at the Gardnerville hatchery with a focus on preserving the species’ unique genetics to enhance conservation and recreational opportunities in Pyramid Lake, Lake Tahoe and Walker Lake. Working alongside the tribe, Service biologists began stocking the strain back into Pyramid Lake in 2006.

Adam Nanninga, FWS fisheries biologist, places Pilot Peak Lahontan cutthroat trout eggs into an incubation tank at the Lahontan National Fish Hatchery Complex in Gardnerville, Nevada. Photo: Dan Hottle/USFWS

In 2014, after several seasons of tagging, tracking and monitoring efforts, spawning-age fish were observed following their historic natural migration route into the lower Truckee from Pyramid Lake for the first time in more than 80 years.

Their first attempt brought them nearly three miles upstream to the Complex’s Marble Bluff Fish Passage Facility, where biologists were able to conclusively document natural reproduction even in the midst of a taxing five-year drought.

This year the migrating Pilot Peak LCT, along with endangered Pyramid Lake cui-ui, are being allowed to progress through the Marble Bluff facility another seven miles upstream to Numana Dam within the reservation boundaries of the Pyramid Lake Paiute Tribe. As the fish pass through, biologists are collecting the trout and implanting internal acoustic transmitters that will return additional migratory information.

A tagged juvenile Pilot Peak Lahontan cutthroat trout at just a few months old. Photo: USFWS

If optimal water conditions continue to facilitate natural reproduction in this stretch of river, the team will evaluate the data they collect and determine how much farther up the Truckee River they can help the fish swim next year. The hope is that the Pilot Peak LCT will soon begin to spawn in the same historic waters as they did as far back as the end of the last ice age more than 10,000 years ago. This is an extremely important fish to the Pyramid people.

Roy Hicks, FWS tractor operator, holds a large spawning-
age Pilot Peak Lahontan cutthroat trout at the Marble Bluff
Fish Passage Facility near Pyramid Lake.
Credit: Tim Loux/USFWS

“Relying on the native cui-ui and the trout is how they used to live, and because of this restoration program, we can give the fish back to our people,” said Albert John, Pyramid Lake Paiute Tribal Fisheries director. “Because of these fish returning in abundance we now have revenues of over $1 million coming into the tribe, and that goes to our social programs, our police and to everyone the tribe supports.”

Stories of "monster" salmon trout weighing up to 60 pounds in the Truckee date back as far as early settlers of the Gold Rush in the mid-1800s, who documented a voracious predator that was as clever as it was abundant. But commercial development of Lake Tahoe at the turn of the century and the demand for the Truckee’s resources for nearby Nevada agriculture took its toll on the fish’s riverine habitat. By 1938 the species had vanished from both Pyramid Lake and the river.

This unique, lacustrine, or lake form, of native trout was first listed by the Service as endangered in 1970 and reclassified as threatened in 1975 and 2008 due to predation by non-native brook and lake trout, hybridization with rainbow trout, water diversion and the declining health of its Truckee River habitat.

More than 30 years later, fish biologist Robert Behnke discovered a population of LCT in a remote stream in the Pilot Mountains bordering Nevada and Utah. He believed they were Pyramid Lake LCT based on the species’ morphological characteristics. When advanced DNA analysis methods were developed in the early 1990s, the Complex initiated a number of genetic investigations to determine their potential origin.

Developing Pilot Peak Lahontan cutthroat trout fry with yolk sacs still attached at 30 days. Photo: USFWS

By 2002, Mary Peacock, a conservation geneticist from the University of Nevada-Reno, was able to extract micro-satellite DNA samples from museum mounts of the original lake populations in both Lake Tahoe and Pyramid Lake. Her analysis showed that the DNA from the museum mounts matched the Pilot Peak LCT and that the broodstock on station was related to the same fabled trout that once roamed the waters of prehistoric Lake Lahontan.

Ensuing support for the LCT’s restoration effort began with Nevada Senator Harry Reid’s backing of the Pyramid Lake/Truckee/Carson Water Rights Settlement Act in 1990, which included, among many other valuable lake and Truckee Basin conservation measures, provisions to enhance the ecosystem flows of the river and to expedite recovery plans for both LCT and Pyramid Lake’s endangered, native cui-ui.

Staff from the Lahontan National Fish Hatchery Complex work to gather data from Lahontan cutthroat trout spawning locations, called “redds,” in the lower Truckee River near Pyramid Lake. Photo: USFWS

Since Behnke’s discovery, the goal of the Complex and the Service’s Fisheries and Aquatic Conservation program has been threefold for the species: conservation, recreation and sustainability.

From an early stage in the recovery process, Heki’s team knew that before they could start reintroducing newly-minted Pilot Peak LCT fry back into Pyramid Lake, an overhaul of the Truckee River basin ecosystem would be necessary.

Eggs from the Pilot Peak strain of Lahontan cutthroat
trout at 14 days. Photo Credit: USFWS

The primary task was restoring key areas of the Truckee River back to the same natural hydrologic characteristics that existed when the trout ran the full span of the river unencumbered by man.

Reversing 80 years of development meant not only managing critical water flows – especially during long drought periods – but restoring the overall ecological health of the riparian “forest” of cottonwoods and other native vegetation that help maintain optimal river depth and temperature fluctuations and provide critical shelter and food.

Heki said that from day one her team was convinced that the key to restoring the iconic Pilot Peak LCT back to Pyramid laid in preserving the genetic legacy that helped them thrive and dominate the lake as the top predator species for thousands of years, shaped a rich heritage for the Paiute people, and spawned more than a few wild fish stories.

“We will continue to keep them wild in anticipation that one day they’ll be able to return year after to year to their historic native waters, not only preserve their cultural history, but to also bring back one of the most valuable and prolific sport fisheries in America,” she said.


Dan Boone, FWS maintenance worker, rinses Lahontan cutthroat trout eggs during spawning operations at the Lahontan National Fish Hatchery Complex in Gardnerville, Nev. Credit: Dan Hottle/USFWS

Stephanie Byers, FWS fisheries biologist, pours a buffer solution into a test tube containing Lahontan cutthroat trout reproductive fluid, called “milt,” at the Lahontan National Fish Hatchery Complex in Gardnerville, Nev. Photo Credit: Dan Hottle/USFWS

Erik Horgen, FWS fisheries biologist, holds a spawning-age Pilot Peak Lahontan cutthroat trout at the Lahontan National Fish Hatchery Complex’s Marble Bluff Fish Passage Facility near Pyramid Lake. Credit: USFWS

Dan Hottle is the public affairs officer for the Reno Fish and Wildlife Office.

 

  • For more information on the Service’s Fish and Aquatic Conservation program visit http://www.fws.gov/cno/fisheries/
  • For more information on the Lahontan Fish Hatchery Complex, visit http://www.fws.gov/lahontannfhc/
  • For more information on fishing at Pyramid Lake and the Pyramid Lake Paiute tribal fisheries program, visit http://www.pyramidlakefisheries.org/
  • For more information on state fishing regulations visit: Nevada at http://www.ndow.org/ and California at https://www.wildlife.ca.gov/