9571

• UCREFRP Catalog Number: 9571
• Author: Miller Ecological Consultants Inc.
• Title: Fryingpan-Roaring Fork Literature Review.
• USFW Year: 2002.
• USFW - Doc Type: Fort Collins, CO.
• Copyright Material: NO

1
1
1
1
1

1

1
Filtration Studies
Filter samples were taken monthly since 1998 from the Fryingpan River immediately
below Ruedi Dam. All of these samples tested negative for the presence of whirling
disease. Samples taken from 1.9 km upstream from the inflow from ponds on the Cap K
Ranch tested positive in 3 of 8 tests performed. The low densities detected indicate that
whirling disease infectivity was very low in the Fryingpan River. Densities of spores
found in the effluent from these ponds had increased over the past yeaz. Water diverted
from the river 3 km downstream from the Cap K Ranch flows through ponds on the Roy
Palm Property, On 7 of 16 occasions the effluent from these ponds tested positive for
whirling disease at very low densities. This indicated that these ponds added very little to
the ambient level of spores present in the river. The site 0.2 km upstream from the
confluence of Taylor Creek had tested negatively for a119 tests in 1999 as opposed to the
4 positive tests in 1998.
Myxospore Burden Studies
Rainbow and brown trout had been screened for the presence of whirling disease in the
Fryingpan River since 1994. Since then the incidence and severity of whirling disease
has been very low. Evidence indicates that the heaviest infection of whirling disease
occurs in the downstream reaches of the river. This indicates two possibilities for the
source of infection: migration of infected trout upstream out of the Roaring Fork River or
a point source of infection within the Fryingpan River. CDOW records indicated that the
river had not been stocked with any infected trout. Ponds on the Cap K Ranch seem to be
a point source of infection. Future studies are planned to develop a system for removing
whirling disease infection from the ponds on the Cap K Ranch and the rest of the river
and also to screen for other sources of infection in local private ponds.
Roazing Fork River
Whirling disease was introduced to the Roaring Fork River when trout exposed to the
parasite were stocked into the river by a private aquaculturist in the late 1980's. Rainbow
trout, brown trout and mountain whitefish tested positive for the presence of cranial
myxospores between 1994 and 1997. Myxospore burdens in all three species were low.
Fryingpan-Roaring Fork Literature Review February 27, 2002
Miller Ecological Consultants, Inc. Page ZS