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

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be eliminated with one or a few threats.
he classification of "threatened" presupposes that a species is no longer in danger of
e n, but is faced with threats that could drive the species to endangerment. Hence, this
classification is based primarily on demographic considerations and minimization or removal of
threats. A species is threatened when any of the following considerations and conditions is met:
. Threats: when threats exist over a significant portion of the range of the species.
. Demographics: when self-sustaining populations remain at low levels, such that
ack of recruitment could severely deplete numbers of individuals.
. n Redundancy: when populations are too few, or too concentrated, to
avert singular threats and long-term viability is not assured.
· Genetics: threatened species exhibit long-term genetic viability.

2.0 DESIGNATION OF RECOVERY AREAS

Three possible recovey areas (RA are recognized in the Colorado River Basin; the
upper Colorado River basin (upper basi stream of Glen Canyon Dam, the lower Colorado
River basin (lower basin) downstream en Canyon Dam to the international boundary with
Mexico, and the San Juan River basin. Each RA contains unique geological and ecological
settings which evolved as a basin-wide continuum, but now exist as discrete and distinct regions
as a result of anthropogenic modifications, primarily large mainstem dams. Glen Canyon Dam is
an impassable barrier that divides the upper from the lower basin, and backs up Lake Powell
reservoir for about 320 km of inundated historic riverine hab lthough the upper basin and
the San Juan River basin drain into Lake Powell above Glen yon Dam, riverine habitats of
these two systems are separated by about 200 km of deep lake habitat, across which movement of
native fishes has not been documented.
In addition to ecological differences between the upper basin, lower basin, and San Juan
River basin, there are distinct programs that administer and coordinate conservation and recovery
of the endangered fishes. Five major programs coordinate and/or conservation andIry
efforts of the endangered fishes in different parts of the Colorado River Basin. These . e the
Upper Colorado River Endangered Fish Recovery Program (UCRRP), San Juan River asin

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