7025

• UCREFRP Catalog Number: 7025
• Author: Hawkins, J. A. and T. P. Nesler.
• Title: Nonnative Fishes in the Upper Colorado River Basin
• USFW Year: 1991.
• USFW - Doc Type: An Issue Paper.
• Copyright Material: YES

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12.) Existing research results confirming wild predation by various introduced species
upon Colorado squawfish, humpback chub, and bonytail chub were exceedingly scarce.
Field investigations should verify, replicate, or expand upon results from controlled field
and lab studies.

Management recommendations

1.) Agencies should not seek to enhance or promote river-based, non-salmonid fisheries
for introduced species, particularly channel catfish, northern pike, smallmouth bass and
walleye until specific research investigations can confirm or deny suspected negative
interactions.

2.) Agencies should seek to maintain and safeguard native fish faunal assemblages in
their native habitat by restricting use of gamefish predators to off-channel water bodies
that are secure from escapement, and identifying and isolating sources of gamefish
escapement from river access. Increased isolation of offstream impoundments is
recommended to prevent escapement of exotic fishes during high flow events.

3.) Agencies should seek to confirm the optimistic estimate of incidental catch of
endangered fishes in the Colorado River in Utah and expand the evaluation to areas of
high angler use in occupied endangered fish habitat elsewhere. Creel survey sample
techniques should be modified with respect to time of day and seasons of highest angler
effort and catch.

4.) Agencies should continue public relations efforts to promote catch and release of
native fish by anglers, and target specific angler groups that have a higher probability of
capturing endangered species.

5.) Agencies should initiate or continue to identify and monitor river reaches in occupied
endangered fish habitat that are susceptIble to periodic and extraordinarily high
incidental catch of endangered fishes, and move to protect these areas from angler use
(e.g. White River closure below Kenney Reservoir).

6.) Agencies should facilitate and promote internal and interagency communication
between nongame/native fish and gamefish management sections to encourage optimal
management guidance for both elements of the aquatic wildlife resource.

7.) Agencies should continue to review proposed and existing stocking practices for both
new and indigenous game fish, forage fish species, and sport fisheries with regard for
potential negative impacts to native and endangered fish communities both on and off-
site. Research should be required to confirm or deny suspected negative interactions.