Poisoning a creek to restore a fish population may sound like a bit of a contradiction, but that’s the plan on a remote section of Silver King Creek in Alpine County.
The California Department of Fish and Wildlife, the U.S. Forest Service and the U.S. Fish and Wildlife Service announced they will move forward with a joint effort to restore Paiute cutthroat trout on an 11-mile section of Silver King Creek June 26. The agencies hope that using Rotenone — a toxin poisonous to fish— on the stream and killing off the introduced rainbow, Lahontan and golden trout species will help the native Paiute cutthroat trout — one of California’s most rare trout species — make a comeback.
The Paiute cutthroat trout was put on the endangered species list in 1967. It was reclassified as threatened in 1975. Biologists fear that interbreeding with non-native trout species could eliminate the colorful stream fish.
“When they’re interbred with Lahontan cutthroat or rainbow trout, the Paiutes tend to lose their distinctiveness through that hybridization,” said Dana Michaels, a spokeswoman for the California Department of Fish and Wildlife.
Once the section of stream, which runs through the Carson Iceberg Wilderness just south of Markleeville, has been poisoned, the agencies will release a neutralizer to mitigate the effects of the Rotenone farther downstream. The agencies will then plant a pure strain of Paiute cutthroat from a population kept in a hatchery or from another section of the river.
“We’ve looked at all the possibilities and have tried other methods, and have come to the conclusion that the only thing that is going to work on a waterway this large and this long is using Rotenone to kill off the other fish,” Michaels said.
The project has been in and out of the courts since 2004. Groups such as the Center for Biological Diversity and Californians for Alternatives to Toxics have sued over different aspects of the plan. A grassroots group called Friends of Silver King Creek also fought against the use of Rotenone on the backcountry waterway. The agencies are through the litigation and will begin the project unless they’re challenged again in the courts, Michaels said.
Fishermen and fishing advocacy groups have supported the plan.
“In this particular case, it’s a good thing because it will increase its habitat,” said Mikey Wier, a spokesman for California Trout, a nonprofit organization that protects and restores wild trout, steelhead and salmon in California.
For local fishermen, the plan means the loss of a great fishery, but also the protection of a unique fish, said Tahoe Fly fishing Outfitters owner Victor Babbit.
“It’s a necessary evil when you’re trying to do something of that nature,” Babbit said. “But poisoning it will have an impact on my business for a term until they can get it open again.”