7893

• UCREFRP Catalog Number: 7893
• Author: Satterfield, J. R., Jr.
• Title: Summary Of Responses, Colorado Division Of Wildlife Lake Management Plans.
• USFW Year: 1994.
• USFW - Doc Type: \
• Copyright Material: NO

9

Many of the plans mention the inability of stocked channel
catfish to compete with wild populations of this species. We are not
aware of any studies that support this statement and suggest that if
it is left in all the plans, a citation or other data be provided to
support this claim. If no such data are available, these references
should be deleted.

Another commonality of these plans is their inadequate treatment
of measures to remedy impacts to endangered fishes if stocked fish
escape and become established in critical habitat. The plans
generally note that stocking will be stopped if stocked fish become a
problem; but, make no mention of actions to remedy impacts in
critical habitat from escaped fish and their progeny. The reality of
this potential problem is that, once a new species becomes
established in critical habitat, it will essentially be impossible to
completely remove it. Channel catfish (in most of the Colorado and
Green Rivers) and northern pike (in the Yampa and parts of the Green
Rivers) are classic examples of this situation. The documents should
all note this inherent risk as well as the real limitations of
removing newly established species if they occur.

We agree with the majority of plans that risks to endangered
fishes from stocking channel catfish, largemouth bass, crappies and
bluegills are minimal. Potential impacts from pure strains of
walleyes are probably also low; however, additional consideration
must be given to stocking this species because of its limited
presence in the basin now and the potential magnitude of impacts if
riverine populations were to become established. As a matter of
note, we seldom find adult walleyes in rivers below reservoirs in
Wyoming with good walleye populations; but, some strains of walleyes
may find riverine habitats more suitable than others. Also, we do
find reasonable numbers of sauger in riverine environments. Impure
strains of walleyes (sauger/walleye hybrids) could pose an elevated
risk to endangered fishes. We recommend plans for stocking walleyes
be delayed until this concern can be more specifically addressed.

We also have the following comments on individual lake management
plans.

Connected Lakes (Small and Large), Duke Lake and Corn Lake

.. .
The species involved (largemouth bass, bluegill and channel
catfish) already occur in the drainage and may be stocked on a
routine basis under certain conditions. The potential for survival
for black crappies, bluegills ~nd largemouth bass in t~e main channel
of the Colorado River is reasonably well addressed; however, some
concern exists about the potential presence of escaped centrarchids
in backwater habitats.