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

There are currently about 12,500 acres of coldwater stream habitat (actual miles not
available, but estimated to be about 3,000) that are stocked with trout. The balance of the stream
miles would be unstocked, less accessible waters. Stocked streams produced about 697,000
recreation days in 1992, or about 14% of total statewide fishing recreation days. It is assumed
that current (1996) recreation days would be much less than this as catchable trout stocking in
streams is now about 70% less than in 1992. Because fish stocking in streams, particularly with
catchable trout, maintains a fish density above the level of natural productivity of that habitat, the
resulting fishing pressure is also "artificially" high as compared with anticipated pressure under
wild trout management. As a result, a change to wild trout management in these waters would
probably result in a decrease of recreation days. A reasonable estimate of this loss based on the
Categorization System would be about 100,000 recreation days.
In some of Colorado's higher quality trout streams, wild trout management with the
addition of special regulations has produced exceptionally good trout populations. These fisheries
are recognized for their quality and fishing pressure that meets or exceeds the fishing pressure
found on heavily stocked streams. Some of the 3,000 miles of currently-stocked streams might be
appropriate candidates for special regulations and could support fishing pressure similar to that
experienced with stocking; however, the actual number of these waters was not determined for
this report.
Although intensive fishery population monitoring would be needed to justify the addition of
new quality fishing in streams using special regulations, the general assessment of DOW
biologists (based on adequate knowledge of their streams' potential) is that we have already
established quality regulations on the vast majority of potential stream segments in the state.
Unless the DOW acquires access to substantial amounts of new private water, there is not likely
much new potential for high quality wild trout habitat present in the state. Therefore, given
existing resources, a switch to wild trout management in streams will generally mean a net loss of
recreation. Further loss to recreation could occur if special regulations were broadly applied to
streams to protect the wild trout (regardless of their quality) from harvest.
It should be recognized that regardless of the actual changes to fishing recreation days that
might occur with a change to wild trout management in streams, currently these streams only
support an estimated 14% of the statewide recreation days. Therefore, any changes to the
management of coldwater streams will not have a large impact on statewide fishing recreation;
however, there will likely be some recognized and contentious disruption of fishing in isolated
areas of the state that are particularly dependent upon stream fishing for stocked trout (Poudre,
Rio Grande, etc.).
Another impact of changing to wild trout management in streams would be the potential
reduction or redirection of hatchery fish that are currently produced to support the existing stream
stocking program. In 1992, streams received most of the statewide trout production--fiy (1%),
fingerling (22%), subcatchable (15%) and catchable (19%). However, because of stocking
changes mandated by WD stocking guidelines in the past couple of years, these percentages
26