Controversial Recovery Plan Proposed for "Rarest Trout in America"

by Sherry Morse

The US Fish and Wildlife Service has proposed a controversial recovery plan for Paiute cutthroat trout, which the USFWS calls "the rarest trout in America." The plan will cost $500,000 and involve poisoning the trout's habitat to kill non-native fish.

Paiute cutthroat trout are native to only a nine mile section of upper Silver King Creek which flows into the Carson River south of Lake Tahoe.

Randi Thompson, a USFWS spokeswoman, said the fact that the trout live in such a small section of one river makes them "the rarest trout in the world, or at least in the US."

According to the USFWS, the trout evolved into a separate species after it was cut off from other waterways about 5000 years ago.

The recovery plan includes poisoning the lower section of Silver King creek to rid it of non-native fish which compete with the Paiute cutthroat for food. Rotenone would be used to poison the creek for up to three years.

Rotenone was used in an unsuccessful attempt to eradicate northern pike from Lake Davis in the Sierra Nevada in 1997. Non-native Silver King Creek trout have survived prior Rotenone poisonings in 1964, 1977 and 1991 to 1993.

The USFWS says the plan will also benefit the rare mountain yellow-legged frog, which seems to cohabitate with the trout, as well as the Yosemite toad.

A lawsuit filed last year prompted the US Forest Service to block the California wildlife department's plan to poison the eleven mile section of the creek below Llewellyn Falls.

The falls form a natural barrier that keeps non-native fish from migrating to the section of the river where the Paiute trout live.

The species was declared endangered in 1970, but in 1975 its status was changed to threatened so that fishing could be allowed.

If the proposed recovery plan's projections are correct, the trout could be removed from the endangered species list by 2013 when it has reached a stable, self-sustaining population level.

Some Paiute trout were transplanted a century ago into four other California waterways where purebred populations survive, but Silver King Creek is the most accessible for fishermen; this is one reason that it is receiving priority treatment by officials.

© 2004 Animal News Center, Inc.