RENO — Lahontan cutthroat trout are successfully reproducing in the lower Truckee River in what experts are calling a major milestone in efforts to restore the population once on the brink of extinction.
Last year, cutthroats raised from a strain of a remnant population in the mountains near the Nevada-Utah line spawned upstream from Pyramid Lake for the first time in nearly 80 years.
Now, U.S. Fish and Wildlife Service officials have documented about 1,000 newly hatched baby cutthroats swimming in the river after a second spawn this spring. They suspect as many as 45,000 may have hatched in recent weeks.
“We were able to document successful reproduction,” said Lisa Heki, complex manager for the Lahontan National Fish Hatchery.
The Nevada state fish, Lahontan cutthroats were listed as an endangered species in 1970 and reclassified as threatened five years later.
“This is a wild reproductive event. The fish are doing it on their own once again,” she told the Reno Gazette-Journal last week.
The lower Truckee River flows out of the north end of Lake Tahoe traveling about 100 miles through downtown Reno before reaching Pyramid Lake.
A successful spawn in the river about 30 miles east of Reno is particularly noteworthy during a fourth year of drought that has significantly lowered water levels, Heki said. She said it suggests the fish population has the necessary resiliency to be self-sustaining.
“Finally reaching this goal is awesome,” said Albert John, fisheries director for the Pyramid Lake Paiute Tribe. “If they can reproduce, that’s been the goal of the tribe since the 1970s.”
Lahontan cutthroats once thrived in all the major rivers and lakes on the eastern side of the Sierra, including Pyramid Lake, Lake Tahoe and the Truckee. Cutthroats — famous for their size and taste — were fished extensively from Tahoe and Pyramid and shipped by rail to 1800s mining camps and to San Francisco.
Overfishing, destruction of spawning habitat and introduction of non-native game fish combined to decimate the cutthroat population. The fish disappeared from Lake Tahoe by 1939 and Pyramid Lake by 1944. Key to their disappearance in Pyramid Lake and the river was the 1905 construction of the Derby Dam 30 miles upstream of Pyramid Lake, diminishing flows to the lake and ruining spawning habitat.
The Pyramid Lake Paiute Tribe established a cutthroat hatchery at Sutcliffe on Pyramid Lake’s shore in 1974, but that strain of cutthroat — originating from outside the Truckee River Basin — has only spawned at the hatchery. The spawns that occurred last year and this spring were the first natural ones since 1938.
The strain of cutthroat that spawned downstream of Marble Bluff, different from the one raised by the tribe, was collected from a stream in the Pilot Mountains on the Nevada-Utah border. DNA testing confirmed those fish were part of the original Pyramid Lake population that disappeared from the lake decades ago.
“They are live, vibrant, and swimming out to the lake for the first time,” Heki said.
In five to seven years, surviving fish will return to the river as adults to repeat the cycle.
“That will be the continuity of a self-sustaining, wild population,” Heki said.