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

H, WHIRLING DISEASE
History of Myxobolus cerebralis in Colorado
On November 25, 1987, Myxobolus cerebralis (MC) was found for the first time in
Colorado at a private facility and a nearby state fish hatchery (Mt. Shavano) close to Salida in the
Arkansas River drainage. In the two weeks that followed, the organism was also found at a
private facility near Creede in the Rio Grande River drainage and at another private fish culture
site on Trout Creek, a tributary of the South Platte River in south central Douglas County. Trout
collected at a private hatchery north of Fort Collins tested positive for WD on December 15,
1987. On February 15, 1988, MC was detected at the Chalk Cliffs Rearing Unit in the Arkansas
drainage. By May 1988, the pathogen had been found at 12 locations in Colorado. The list
included two state facilities, nine private commercial fish farms, and one private pond on the Air
Force Academy. Within a year (1989) 26,262 fish had been sampled for WD from 48 fish culture
sites and 182 free-ranging populations. Eleven fish culture sites and 40 free-ranging trout
populations (Appendix A) found in 11 of the 15 major drainages tested positive (Appendix B).
All fish culture sites found positive for WD were immediately quarantined by order of the
director. Presently, the DOW categorizes the WD status of the state's waters using "water codes"
(DOW identification system for lake and stream segments).
In November 1987, the DOW employed one full-time fish pathologist and received
assistance from the U.S. Fish and Wildlife Service's (USFWS) Fish Health Laboratory in Ft.
Morgan, Colorado. After WD was found in Colorado, the DOW immediately rented laboratory
space to start a WD diagnostic center and hired three temporary employees under the direction of
the state fish pathologist to staff the facility. The USFWS provided the services of a certified fish
pathologist for one year to assist in determining how widespread WD was in Colorado. The
Director of the DOW also initiated a task force to guide the program. The task force consisted of
one lawyer from the attorney general's office, a DOW fish pathologist, one person from the Law
Enforcement Section, two fish researchers, a USFWS fish pathologist, one employee from the
Public Affairs Section; and other individuals from within and outside the DOW, as needed. The
whole group was under the direction of the state fish manager. Also, as required by regulation,
other government agencies were consulted in the decision-making process. Total effort, minus
legal services, on WD in Colorado from November 24, 1987, to July 31, 1988, amounted to
7,600 hours of labor and an expenditure of $172,000.
An emergency conference on WD held in Denver on April 12-14, 1988, was attended by
approximately 70 people representing university and agency research communities, as well as a
variety of state, federal, and private fishery programs. The Colorado River Fish and Wildlife
Council (CRFWC) fish disease subcommittee conducted the meeting and, with the information
generated, developed a conference statement that was presented to all fish health representatives
of the member states for discussion as well as the entire assembled group. Minor changes were
suggested and incorporated by the committee.
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