9439

• UCREFRP Catalog Number: 9439
• Author: Upper Colorado River Endangered Fish Recovery Program.
• Title: Nonnative Fish Control Workshop
• USFW Year: 2002.
• USFW - Doc Type: Summary, Conclusions, and Recommendations.
• Copyright Material: NO

EXECUTIVE SUMMARY
The Upper Colorado River Endangered Fish Recovery Program (UCRRP) convened a Nonnative
Fish Control Workshop on February 13-14, 2002, in Grand Junction, Colorado. The purpose of
the workshop was to bring together fish researchers and managers to discuss and evaluate
nonnative fish control efforts implemented to date in the Upper Colorado River Basin.
Information exchanged at the workshop will be used to modify and refine tasks of the Nonnative
and Sport Fish Management element of the UCRRP's Recovery Action Plan (RIPRAP). Tasks
of this element are designed to reduce negative impacts of problematic nonnative fishes on the
endangered Colorado pikeminnow (Ptychocheilus lucius), razorback sucker (Xyrauchen
texanus), humpback chub (Gila cypha), and bonytail (Gila elegans).
The following conclusions were reached from presentations and discussions at the workshop:
• I&E efforts need to continue to improve to be more effective at targeting the
various public groups with appropriate information on the intent, activities, and
planning of the nonnative fish control. The nonnative fish control program is in
the initial stages of development and evaluation, and the public needs to be
advised and informed about the program.
• The 1996 Nonnative Fish Stocking Procedures are too complex.to be translated
into understandable and enforceable State regulations. It was noted that in all
nonnative fish control efforts, there is a need to demonstrate measurable effects of
the action.
• Of the 335 ponds investigated to date in the Grand Valley, studies have shown
rapid re-invasion of most reclaimed ponds by small cyprinids and green sunfish;
limited use of sampled ponds by largemouth bass; and difficulty in maintenance
and enforcement of maintenance of outlet screens.
• Based on results at Old Charlie Wash on the Green River, it is feasible to remove
large numbers and biomass of nonnative fishes from managed/controlled
floodplain depressions, but the effects of this removal on main-channel fish
populations is unknown.
• Studies have shown that the Highline Lake Fish Barrier Net is effective at
minimizing escapement of nonnative fishes from Highline Lake.
• Efforts in the Yampa River to remove/translocate northern pike have received
positive public feedback; data suggest depletive effects.in habitats sampled over
the sampling period, but average size of northern pike and incidence of attacks on
Colorado pikeminnow have increased. Implementation of a bounty reward for
northern pike removed through recreational angling may have potential.
• There have been substantial increases in smallmouth bass populations in the
Yampa River.
• Fish sampling conducted in the Gunnison River downstream of Hartland
diversion since 1996 has not collected northern pike, suggesting that efforts
during 1995-1996 to remove the species from this river reach were successful.
• Methods used in 2001 to remove northern pike from the middle Green River
appear to be appropriate.
11
11

1

1
1

1

1

1