9383

• UCREFRP Catalog Number: 9383
• Author: SWCA, I.
• Title: Recovery Goals for the four Colorado River Endangered Fish Species.
• USFW Year: 2000.
• USFW - Doc Type: Logan.
• Copyright Material: NO

the trend in adult population point esti
decline significantly, and
c. the proportion of age 3 fish is not significantly lower than 25% of the adult

s for the same 8 years does not

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4.1.2.2 Delistine Criteria. The humpback chub will be considered for delisting when the

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'!following criteria are met:
All Populations
1. Maintain all five known upper basin populations such that:
a. the trend in population point estimates for the 8-year monitoring period
does not decline significantly (based on estimates in Table 3 or best first
estimate), and
b. e proportion of age 3 fish for is not significantly lower than 25% of the
" ult population for 4 of the same 8 years (see Table 4 and Statistical
~1~
Guidelines).
2. Provide legal protection, assurances, and/or agreements for flows necessary to
recover and conserve the humpback chub.
3. Review and modify, if necessary, state and federal hazardous spills emergency
response plans to insure adequate protection from spills, including prevention and
quick response to spills.

4.

Implement nonnative fi

01 in Yampa Canyon, Grand Canyon, and

Desolation/Gray Canyons, as needed.
Core Populations
1. Maintain three core populations such that:
a. the lower 95% confidence interval of the estimate exceeds 2,100 adults for
a period of 8 years,

b.

population for 4 of the same 8 years (see Table 3 and Statistical
Guidelines).
Lower Colorado River Basin
At least two actions have been identified to increase the numbers, range an~
populations in the lower basin. One action is to modify the temperature of released ~r from

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