[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

NFC: DP whirling disease


TU has released a comprehensive new report detailing the current knowledge
about whirling disease, the parasitic infection that has been linked to
dramatic declines in wild trout populations in several Western rivers.

"Whirling Disease in the United States," an update of TU's groundbreaking
1995 report on whirling disease (WD) in America, summarizes what has been
done to better understand WD and its implications for wild trout fisheries
nationwide, and updates the state of whirling disease science. The report is
the most complete synthesis of the science and management of Myxobolus
cerebralis since 1995, when the discovery of WD in wild trout in Montana and
Colorado spurred accelerated research into the disease.

"Researchers must continue to move forward on the research priorities already
identified, and assess possible management strategies and their effectiveness
in the wild," said Charles Gauvin, TU's President and CEO. "New knowledge
about the importance of habitat degradation (in providing Tubifex habitat),
environmental stress, and disease 'point sources' all suggest that our
ability and willingness to protect and restore our streams and rivers may
prove the best long-term protection against whirling disease."

Significant research results described in the report include new evidence
that the Tubifex worms that carry WD appear to thrive in polluted or degraded
streams. Studies of T. tubifex worms in Montana found that worms are
primarily found in polluted sites where normal benthic community diversity
had been reduced.
Research in Colorado has found infection "point sources"-locations where
production of triactinomyxons (the spores that cause the disease) is high and
the disease is especially severe.

Researchers have also developed a DNA-based test to detect the parasite, and
have established that most salmonid fishes are susceptible to the infection,
to varying degrees. Key research has also focused on the role of water
temperature on the numbers of disease spores found in a given stream or water

"Whirling Disease in the United States" documents the investments in research
and the changes in fisheries management that many states have made in the
wake of the WD crisis, singling out Colorado, Idaho, Utah, and Montana as
examples, while pointing out that much remains to be done to safeguard
remaining wild trout populations.

The report also points out the contradictory actions taken by federal
agencies in dealing with WD. The U.S. Fish and Wildlife Service has supported
research at several top laboratories and has also supported a competitive
grants program through the National Partnership on the Management of Wild and
Native Cold Water Fisheries. The National Partnership has provided over
$920,000 in competitive grants to support WD research, leveraging more than
$880,000 in matching funds.

By contrast, the Forest Service and Bureau of Land Management (BLM) have been
less helpful. In 1988 the Forest Service prepared an Environmental Assessment
that permitted the stocking of WD-infected fish on Forest Service and BLM
lands. It is the current policy of both agencies that if a state wishes to
stock fish exposed to WD on public lands, it may do so without additional
environmental review.

Copies of "Whirling Disease in the United States" may be obtained upon
request from TU at (703) 522-0200; mailto:trout at tu_org, and may be downloaded
in Adobe .pdf format from TU's Web site at