9594

• UCREFRP Catalog Number: 9594
• Author: Colorado Division of Wildlife and e. al.
• Title: Procedures for Stocking Nonnative Fish Species in the Upper Colorado River Basin.
• USFW Year: 1996.
• USFW - Doc Type: \
• Copyright Material: NO

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recent information that demonstrates competition between
young-of-the-year Colorado squawfish and fathead minnow. The
fathead minnow is also a predator that attacks fish larvae and
tears the larvae into pieces. The fathead minnows then eat the
pieces so that the gape of the mouth is not important in the size
of the larvae that are consumed.
Channel catfish: This species has been introduced into the
mainstem rivers, lakes, reservoirs, and ponds in the Upper Colorado
River. Their diet includes other fishes and are considered a
threat to the endangered fishes. Channel catfish were ranked 1st
on the list of 28 nonnative fish species considered to adversely
impact the native fishes in the Colorado River Basin (Hawkins and
Nesler 1991).
6. Public and private waters that have a direct connection to rivers
in the Upper Colorado River Basin (e.g., Elkhead Reservoir,
Highline Reservoir, and many ponds) will be equipped or managed
with an anti-escapement device or practice acceptable to the
Service and the State fish and wildlife agency. Lake Management
Plans will be prepared or revised and approved by the Service and
the State fish and wildlife agency before the continued stocking of
nonnative, warmwater fish species will be allowed. The Program
will pursue funding for equipping public reservoirs with
anti-escapement devices.
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Stocking of nonnative fishes in public waters, not prohibited, that are
not managed in the Upper Basin at the present time will require
evaluation by the State wildlife agency and the Service on a
case-by-case basis to ensure that the proposed stocking of these fishes
will not adversely affect the endangered fishes. Minimum criteria for
stocking will include: 1) no stocking of isolated ponds within the
50-year floodplain and 2) if the water has an outlet it must be
screened or managed to control escapement. Stocking should be
"confined to areas where absence of potential conflict with rare or
endangered species can be demonstrated" (U.S. Fish and Wildlife Service
1987). The intent here will be to address escapement potential.
1. Requests to stock nonnative fish species that are not prohibited in
the Upper Basin in locations or situations not listed in Section IV
will be evaluated on a case-by-case basis and will include the
following information:
A. The purpose and location of the proposed stocking.
B. The species, numbers, and rationale for selecting the species.
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