WSP02092

• File Number: 8240.200.10.A
• Description: UCRBRIP Program Guidelines
• Basin: Colorado Mainstem
• Date: 12/20/1988
• Author: USDOI/FWS
• Title: Historic Background Statements
• Water Supply Pro - Doc Type: Publication

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Westwater Canyon, Black Rocks Canyon, Cataract Canyon, Desolation Canyon, Yampa
Canyon, and Little Colorado River (Wydoski, "Coordinated Hatchery Facility Plan: Need
for Captive-Reared Endangered Fishes and Propagation Facilities," May, 1994).

3. An aggressive program for stocking of bony tails should be initiated by the Recovery
Program to recover this species by the year 2003.

Rationale: The bonytail is extinct in the upper basin and wild populations appear to be extinct in
the lower basin. The only population existing in the lower basin is in Lake Mohave. This
population is probably derived from Dexter National Fish Hatchery stock (Wydoski, personal
communication, 1996). The Recovery Program Biology Committee (Biology Committee, 1996)
has recently made a recommendation to develop an upper basin brood stock, and a proposal has
been made to stock up to 2,000 bonytail in the Green River at Professor Valley, Utah, as part of
the "Bonytail Reintroduction Plan" (Lentsch, 1996). The Bonytail Reintroduction Plan is not a
stocking plan, but is a research project. It results in stocking of only 34,000 six-inch bonytail
chub at four different sites through 1998. Given the estimated survival rates (Lentsch, 1996), this
would result in an estimated population of about 400 adult bonytail spread over four different
locations. The Bonytail Recovery Plan (USFWS, 1990) states "it is anticipated that at least ten
years of captive propagation will ultimately be required." The reintroduction plan does not begin
to meet a definition of recovery.

Consistent with the recovery plan, the Recovery Program needs to develop a full-scale stocking
program for bonytail, along with other recovery efforts, that will result in recovery by 2003. The
plan needs to identify all facility needs, costs, and stocking locations that are needed to recover
the bonytail.

4. The Recovery Program should initiate large scale, long-term stockings of razorback
sucker in the Green and Colorado River subbasins in order to avoid extinction and achieve
recovery. .

Rationale: The razorback sucker was listed October 23, 1991. Section 4 of the ESA requires the
immediate completion of the razorback sucker recovery plan. A draft of this plan is scheduled for
public release in October, 1996 (Shanks, personal communication). The razorback sucker has
been extirpated on the Colorado and Gunnison Rivers and the only remaining population is a few
hundred adults on the Green River. This results from the fact that 90 to 99 percent of the fish in
the backwaters are nonnatives (ISMP, 1996) which compete with and prey upon larvae and young
of razorback sucker. Spawning has been documented, but there is virtually no survival of the
spawn.

Razorback sucker brood stocks are available, yet the Recovery Program has set extremely limited
stocking goals. These goals include bringing the population back to 1,000 adults in the Green
River and only limited experimental stocking on the Gunnison and Colorado rivers.

The current goal for augmentation stocking in the Middle Green River is to increase the number
of adult razorback suckers with the intent of stabilizing that stock from the present estimate of
500 fish to 1,000 fish. The main objective is to augment the number of adult razorback suckers in

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