DENVER A 20-year government effort to restore the
population of an endangered native trout in Colorado has made
little progress because biologists have been stocking some of the
waterways with the wrong fish, a new study says.
Advances in genetic testing helped biologists discover the error,
which was called a potential black eye, but they said there is
still hope for restoring the greenback cutthroat trout.
The three-year study, led by University of Colorado researchers
and published online in Molecular Ecology on Aug. 28, said that
five of the nine populations believed to be descendants of the
endangered trout were actually the more common Colorado River
cutthroat trout, which look similar.
The study said the results imply that the effort has "failed to
improve the species' status.''
Lead author Jessica Metcalf, who recently completed her
doctorate in ecology and evolutionary biology at the university,
was optimistic about the ongoing restoration program because four
populations have been identified as "pure greenback cutthroat
Bruce Rosenlund of the U.S. Fish and Wildlife Service, which is
leading the recovery effort, said the agency is reviewing the
"The report is just a continuation of different expert input
provided to the team for consideration for restoration,'' Rosenlund
Colorado and federal biologists have a goal of 20
self-sustaining populations of at least 500 fish each. The cost of
the program was not available.
Greenback cutthroat trout were historically found in the
drainages of the Arkansas and South Platte rivers in Colorado and a
small part of Wyoming. They were declared extinct in 1937 because
of overfishing, pollution from mines and competition from nonnative
Researchers said remnant populations were found in the 1950s in
tributaries and provided brood stock for fish raised in federal and
state hatcheries and released in their native habitat.
The fish was added to the federal endangered species list in 1978.
The greenback were believed to be in 142 miles of waterways,
including in Rocky Mountain National Park, Rosenlund said.
The new study, based DNA test results, found the greenback
cutthroat trout's range is only 11 miles of streams.
The research results are a setback but state biologists believe
the program will succeed over the long term, said Tyler Baskfield,
Colorado Division of Wildlife spokesman.
"We've been moving fish around in the state since the late
1800s, and now the new science comes in and all of a sudden it's a
different playing field,'' Baskfield said.
University of Colorado professor Andrew Martin, the study's
principal investigator, said that while the findings might give the
recovery program a "black eye,'' the hope is that biologists and
agencies will move ahead on recovering the species before it goes