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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a. The trend in adult (age 4+; >200 mm TL)~point estimates does not
decline significantly, and
b. Mean estimated recruitment of age-3 (150-199 mm TL) naturally
produced fish equals or exceeds mean annual adult mortality, and
c. Each core population estimates exceeds 2,100 adults (MVP)
Razorback sucker
Overview:
1. Genetic variability of razorback sucker in Lake Mohave is identified, and a
genetic refuge is maintained over a 5-year period.
2. Two self-sustaining populations are maintained over a 5-year period.
Downiisfing Criteria:
1. Genetic variability of razorback sucker in Lake Mohave is identified, and a
genetic refuge is maintained over a 5-year period.
2. Two self-sustaining populations (e.g. mainstem and/or tributaries) are
maintained over a 5-year period, starting with the first point estimate acceptable
to the Service, such that for each population:
a. the trend in adult (age 4+;>400 mm TL) point estimates does not
decline significantly, and
b mean estimated recruitment of age-3 (300-399 mm TL) naturally
produced fish equals or exceeds mean annual adult mortality, and
c. Each point estimate exceeds 5,800 adults (MVP).
Delisting Criteria:
1. A genetic refuge is maintained in Lake Mohave over a 3-year period beyond
delisting.
2. Two self-sustaining populations (e.g., mainstem and/or tributaries) are
maintained over a 3-year period beyond downlisting, starting with the first point
estimate acceptable to the Service, such that for each population:
a. the trend in adult (age 4+; >400 mm TL) point estimates does not
decline significantly, and
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