8057

• UCREFRP Catalog Number: 8057
• Author: Bennett, J. R., D. A. Krieger, T. P. Nesler, L. E. Harris and R. B. Nehring.
• Title: An Assessment Of Fishery Management And Fish Production Alternatives To Reduce The Impact Of Whirling Disease In Colorado.
• USFW Year: 1996.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

EXECUTIVE SUMMARY
The introduction and spread of whirling disease (WD) in Colorado has created widespread
concern and controversy within scientific and public circles. In April 1996, Division Director
John Mumma created A review panel of Division of Wildlife (DOW) staff to conduct an
assessment of WD issues and impacts related to (1) the management of native cutthroat and wild
trout; (2) the reliance of sportfishing recreation on trout stocking; (3) the role and operation of
the state's hatchery system; and (4) the demand for hatchery-raised products like catchable trout.
The Director asked this panel to develop alternative approaches to deal with each of these issues,
and to provide preferred alternatives. The panel members came from a diversity of backgrounds:
regional administration, fisheries research, sportfish management, state hatchery propagation, and
native wildlife conservation.
The panel gathered data and information from a broad base of scientific literature, reports,
unpublished data, and communications with staff and field personnel in DOW's Aquatic Wildlife
Section. The panel was asked to build upon the assessments provided in previous reports
prepared by Deloitte and Touche in July and November 1995. Taken together, all of this
information contributed significantly to the panel's assessment of the major issues and
development of alternative strategies. The first draft of this report received peer review from a
select group of biologists and consultants from both inside and outside the DOW. Input from
DOW Aquatic Wildlife Section personnel was also encouraged. The second draft received a
broader technical peer review from scientists working for other state wildlife agencies, federal
land management agencies, and universities. This final version of the document, which
incorporates the thoughtful comments and concerns voiced by many scientists and other
reviewers, represents our best current understanding of the WD issue in Colorado.
Overview
The DOW is mandated to manage Colorado's wildlife resources from both a conservation
and recreational perspective. This dual mission is emphasized in the 1994 Long-range Plan, and it
is central to the controversy surrounding WD as the DOW attempts to balance resource
protection with fishing recreation. The 1994 Plan directs the DOW to protect and enhance the
viability of all of Colorado's wildlife species, diversify fishing opportunities, increase participation
in fishing in proportion with human population growth, increase angler satisfaction, stock fish as
appropriate to maintain angler satisfaction, and protect and improve high-priority aquatic habitats.
Further direction for DOW related to stocking fish comes from Commission Policies D-1, 2, 4, 6,
and 9, and Administrative Directive F-1.
Currently, WD is known to exist in 1.3% of coldwater stream habitat and 9.1% of coldwater
lake habitat. Since 1988, an estimated 2,550 stream miles have been exposed to the WD parasite.
The trout populations in five major streams in Colorado demonstrate significant population level
declines from WD infection. Evidence in Colorado and elsewhere now refutes the belief that WD
does not negatively impact wild trout populations.
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