Bringing back a native; Researchers attempt to reintroduce Lahontan cutthroat
Fallen Leaf Lake was stocked with more than 43,000 fish in the last two years — all of them Lahontan cutthroat trout, a fish native to the area and listed as threatened by the federal government.
Introduction of nonnative fish such as the mackinaw, coupled with too much fishing of the tasty cutthroat, wiped out its population in lakes such as Tahoe and Fallen Leaf by the 1930s.
Research indicates the cutthroat has the best chance of recovery in small lakes such as Fallen Leaf. It is unknown, however, if any of the thousands of fish planted in the lake last year survived, said Will Cowan, a U.S. Fish and Wildlife Service biologist.
But armed with data provided by the UC Davis Tahoe Research Group, the agency took a different approach at the lake this year by planting cutthroat 10 inches or greater. Last year the fish planted were 8 to 14 inches. The data indicates mackinaw won’t be as likely to make lunch out of the cutthroat if they are at least that size.
“That’s really one of the major findings we had,” said Jake Vander Zanden, who studied the cutthroat at Davis before taking a job as an assistant professor at the University of Wisconsin.
Vander Zanden said he “absolutely” believes the cutthroat, which can grow up to 40 pounds and is named for the red streak under the fish’s mouth, has a chance of re-establishing itself at Fallen Leaf Lake.
The more than 7,000 cutthroat planted by Fish and Wildlife this summer have yellow tags on their top fin. While it’s legal for anglers to catch them, the agency wants to know if one is caught and asks whoever catches one to call the phone number printed on the yellow tag.
“It’s not mandatory,” said Will Cowan, biologist with Fish and Wildlife, based in Reno.
Tiny coded tags implanted in the snout of the cutthroat could also help the agency track the fish. If an angler catches one, it may be helpful to save and freeze the fish’s head so biologists can analyze it.
Cutthroat populations exist in Pyramid Lake, Walker Lake, and a number of river basins in the Central Sierra Nevada.
In 2002, Fish and Wildlife planted more than 36,000 cutthroat in Fallen Leaf. The agency dramatically reduced the number planted this year because they only planted fish at least 10 inches long. Next summer, by making adjustments at the hatchery, they plan to raise enough 10-inch fish to put 20,000 cutthroat in the lake.
The fish are grown near Gardnerville at the Lahontan National Fish Hatchery. It costs about $100,000 to raise a year’s supply for Fallen Leaf.
There are no immediate plans to re-establish cutthroat in Lake Tahoe. Researchers say they want to learn from the Fallen Leaf experiment first.
“Within the next five years we’ll hopefully learn more about the interaction of the mackinaw and the cutthroat and make a better-informed decision,” Cowan said.
The community of Fallen Leaf Lake is behind the effort to bring cutthroat. A number of residents turned up for the fish planting on Friday, the last of the season. Lake Tahoe Unified School District students, in partnership with Geoff Beer of Trout Unlimited, has also helped the effort by releasing 1,500 baby cutthroat in Glen Alpine Creek, which empties into Fallen Leaf.
— Gregory Crofton can be reached at (530) 542-8045 or by e-mail at firstname.lastname@example.org