WSP12913

• File Number: 8240.200.10.A
• Description: Colorado River Endangered Fish Recovey Program
• Basin: Colorado Mainstem
• Date: 9/1/2003
• Author: UCRBRIP
• Title: Recovery Program Director's Update September 2003
• Water Supply Pro - Doc Type: Report/Study

Ralph Morgenweck
Chairman,
Implementation Committee

~~ Upper Colorado River
Endangered Fish
Recovery Program

Robert Muth
Director,
Recovery Program

U.S. Fish and Wildlife Service. P.O. Box 25486 . Denver Federal Center. Denver, CO 80225 . [phone] . Fax [phone]

RECOVERY PROGRAM DIRECTOR'S UPDATE

September 2003

Status of the Endant!ered Fishes

Table 1 presents the most current estimates of the mean number of wild adults in populations of
Colorado pikeminnow and humpback chub, and provides a general overview of efforts to
augment or reestablish razorback sucker and bonytail populations in the Upper Colorado River
Basin (see Table 2 for 2003 stocking summary). Wild populations of Colorado pikeminnow and
humpback chub have been studied since the 1960s, and population dynamics and responses to
management actions have been evaluated since the early 1980s, It is anticipated that self-
sustaining populations of razorback sucker and bonytail will be reestablished over the next 15
years, during which time population dynamics and responses to management actions will be
evaluated. Regions 6 and 2 of the U.S. Fish and Wildlife Service (Service) are collaborating to
ensure a coordinated effort to achieve the recovery goals in both the upper (including the San
Juan River) and lower basins.

As stated in the recovery goals for the four endangered fishes, the Service considers a reliable
population estimate as one that is based on a multiple mark-recapture model. Monitoring must
be designed to determine if the demographic criteria of the recovery goals (see attachment) are
being met. Accordingly, in the Upper Colorado River Basin, closed-population, multiple mark-
recapture estimators are being used to derive populat~on point estimates for Colorado
pikeminnow and humpback chub (see section V). Population and demographic data collected
through monitoring will be used to track progress toward achieving the recovery goals. The
accuracy and precision of each point estimate will be assessed by the Service in cooperation with
the Recovery Program and in consultation with investigators developing the point estimates and
with qualified statisticians and population ecologists. Such an assessment will occur in 2004. In
addition to the demographic criteria, the recovery goals identify site-specific management
actions/tasks ("recovery factor criteria") to minimize or remove threats (see attachment). Details
of these and other management actions/tasks that contribute to recovery in the upper basin are
identified in the Recovery Program's Recovery Implementation Program Recovery Action Plan
(RIPRAP).

Colorado River Energy Distributors Association. Colorado Water Congress. Environmental Defense. National Park Service
State of Colorado. State of Utah. State of Wyoming. The Nature Conservancy. U.S. Bureau of Reclamation. U.S. Fish and Wildlife Service
Utah Water Users Association. Western Area Power Administration. Wyoming Water Association