9384

• UCREFRP Catalog Number: 9384
• Author: Valdez, R. A. and R. J. Ryel.
• Title: Summary of Recovery Goals for the Four Endangered Fishes of the Colorado River Basin.
• USFW Year: 2000.
• USFW - Doc Type: Logan.
• Copyright Material: NO

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Razorback Sucker - 3

Upper Colorado River Subbasin
1. A minimum estimated population of 4,500 adults for a period of 5 years, such
that:
a. the lower 95% confidence interval of the estimated population of adults
exceeds 4,500,
b. a trend in adult population point estimates for the same 5 year period that
does not decline significantly, and
c. a proportion of age 3 fish for each year that is not significantly higher than
30% or lower than 20% of the adult population for the same 5-year period.
2. Provide flows necessary to recover the razorback sucker, including tributaries
necessary to life history; i.e., Gunnison River.
3. Procure and protect habitats necessary to recover the razorback sucker, including
flooded bottomlands.
4. Implement activities to successfully expand the range of the population ofthe
Colorado River subbasin and enhance recruitment; i.e., maintain unimpeded fish
passage within occupied habitats; insure passage over Grand Valley Diversion,
Price-Stub Dam, Government Highline Dam, Redlands Diversion; minimize
entrainment in the Grand Valley Canal.
5. Implement nonnative fish control, as needed, to recover the razorback sucker.
6. Investigate and determine if selenium has a significant negative effect on
reproductive success and survival of razorback sucker.

San Juan River Subbasin
1. Continue activities in the San Juan River to obtain a positive biological response
toward establishing a natural self-sustaining population.
2. Implement nonnative fish control, as needed, to recover the razorback sucker.

Gila River Subbasin and Lower Colorado River
1. Two populations, each with a minimum estimated number of 4,500 adults for a
period of 5 years, such that:
a. the lower 95% confidence interval of the estimated population of adults
exceeds 4,500,
b. a trend in adult population point estimates for the same 5-year period that
does not decline significantly, and
c. a proportion of age 3 fish for each year that is not significantly higher than
30% or lower than 20% of the adult population for the same 5-year period.
2. Procure and insure flows necessary to recover the razorback sucker.
3. Procure and protect habitats necessary to recover the razorback sucker, including
repatriation of flooded bottomlands.
4. Implement nonnative fish control, as needed, to recover the razorback sucker.