9552

• UCREFRP Catalog Number: 9552
• Author: U.S. Fish and Wildlife Service.
• Title: Management Plan for the Big-River Fishes of the Lower Colorado River Basin
• USFW Year: 2004.
• USFW - Doc Type: amendment and supplement to the Bonytail, Humpback chub, Colorado pikeminnow, and Razorback sucker Recovery Plans.
• Copyright Material: NO

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necessa to lessen human or natural) caused erturbations. There
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would be periodic mixing of fish between long-term habitats in accordance
with a genetic management plan, but no other movement of fish would
occur. The fish from these habitats would contribute to genetic diversity
' during periodic mixing with mainstem populations.
2. Producf~on habitats are designed to raise wild-born or hatchery-
~ produced fish to stocking size for release into the mainstem populations or
' to establish long-term habitats. When a large number of fish suitable for
stocking are present they would be harvested and released. The facility
' would then be re-stocked to initiate another production cycle.
Requisite to the success of this plan is the continued maintenance of these
isolated habitats. This includes periodic evaluation and renovation of habitats
' and their fish populations as follows:
' 1. It is anticipated that, over time, nonnative fish species will invade the
isolated habitats. The interactions of the native and nonnative fishes in
the habitats will be studied, particularly with regard to the larger nonnative
' predators, to assess interactions between species. Renovations to
remove the nonnative fish from native fish habitats will occur as needed.

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2. Repeated translocations of native fish from the habitats will be
necessary with attendant needs for genetic, population, and production
planning. The types and frequencies of fish movement will vary depending
on planning needs and the type of habitat involved.
3. Physical maintenance of the habitats will be necessary over the life of
the plan. Construction of new habitats and rehabilitation of existing
habitats will require dry-land excavation or dredging to provide proper
water depths and bottom contours, eliminate excess marsh vegetation
encroachment, and maintain inlet and outlet works. Habitats will be
physically managed in concert with wetland and riparian restoration
programs to enhance ecosystem values.
Strategy 3: Unique Opportunities
The third strategy exploits unusual circumstances. Original persistent adult
reservoir populations of "big-river" fish in the lower Colorado River reservoirs
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