8118

• UCREFRP Catalog Number: 8118
• Author: Mueller, G. and E. Wick.
• Title: Testing of Golf Course Ponds at Page, Arizona for Suitability as Grow-Out Facility for Razorback Sucker Using Surplus Fish from Ouray National Fish Hatchery.
• USFW Year: 1998.
• USFW - Doc Type: Denver, CO.
• Copyright Material: NO

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Stocking Opportunities for the Razorback Sucker

AUimentation of Reservoir Populations Lake Powell impounds water from both the Colorado
and the San Juan Rivers. Both these areas contain habitats suitable to sustain adult population.
Information collected from the San Juan studies suggest that the establishment of reservoir
populations would also result in sucker migrating further upstream in more natural habitats.

-San Juan Inflow Area-The stocking of either the inflow area or upper reaches of the San Juan
River would increase the occurrence of razorback suckers inside the Park. There have been
discussions concerning the reestablishment or expansion of an adult razorback sucker population
in the San Juan Arm of Lake Powell. The inflow area was actually the location where San Juan
razorback suckers were last collected for brood stock in 1991 (Stangl 1993). To our knowledge,
no wild fish have been captured in the past six years.

A Memorandum of Agreement was developed between National Parks Service, Fish and Wildlife
Service, and Utah Department of Natural Resources in 1996. The agreement identified that
surplus production of razorbacks from the upper basin RIP could be stocked into a designated
critical habitat (San Juan Arm) of Lake Powell. The agreement does not specifically include the
golf course ponds, only the disposition of surplus fish. Although a Memorandum of Agreement
exists, the administrative process to move fish back into Lake Powell from the golf course ponds
is complex and involves the issuance of four special use permits. State health certification
required to bring fish into Utah, requires the sacrifice of a minimum of 50 fish for inspection.

Recent telemetry studies have shown that sucker stocked in either the reservoir or river could
travel significant distances and intermix (Ryder 1997, Mueller and Wydoski 1995, Karp and
Mueller 1996). If a goal of augmenting the reservoir population was developed separately from
the RIP, the expansion of reservoir numbers could also benefit San Jan RIP goals. Some fish
stocking further upstream would undoubtedly be lost as some fish migrated into the reservoir.
These numbers could be offset by establishing reservoir populations which would also migrate
upstream. There is information that suggests that in some instances the inflow area might actually
provide adults a refuge from high turbid flood flows (Karp and Mueller unpublished data).

The San Juan RIP recently released a draft augmentation plan that calls for the introduction of
several thousand, large razorback suckers (Ryder 1997). Stocking criteria identifies the use of
fish propagated from upper basin brood stocks or suckers naturally spawned in Lake Mohave.
Regardless, of whether fish are stocked in the reservoir or further upstream, the end result will
undoubtedly be more razorback suckers in Lake Powell.

-Colorado River Inflow Area- In the early to mid-1980, several razorback suckers were captured
near the confluence with the Dirty Devil River (Stangl 1993). Some of these fish were emitting
gametes at the time of capture. During the past 10 years, we are not aware of any coordinated,
nor large scale efforts to collect razorback suckers in the Colorado inflow area. Biologists have
sampled shoreline habitats using seines to capture juvenile Colorado squawfish. Juvenile

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