9681

• UCREFRP Catalog Number: 9681
• Author: Burdick, B.
• Title: Biological Criteria For Use Of Fish Passage In The Recovery Of Threatened and Endangered Fishes in the Upper Colorado River Basin - Draft.
• USFW Year: 1988.
• USFW - Doc Type: \
• Copyright Material: NO

should be expected to provide for fish passage. If information is
known about the performance of squawfish to use a fishway, the
proponent will be more likely to "buy off" on this conservation
measure. If not, the entity that accepts responsibility, whether
it be the project proponent or the Service, will be less likely to
support construction of a fish passageway, realizing that the risk
of failure is high and the chance of successfully passing fish
over a high structure is low. Because there is no information
about the performance of squawfish to use a passive fishway,
selection of another method that would provide passage with
minimum risk of failure should be considered. The recommendation
would be to construct a trapping facility at the base of the
barrier and either actively lift the fish by elevator or bucket;
or truck the fish to the head of the reservoir, if one exists
upstream of the barrier.
3. Biological benefits using a fish passageway:
1) Population "maintenance". This is considered maintaining the
population at status quo. Allow and maintain undisrupted movement
to priority areas presently occupied, either to enable upstream
movement of adults to known spawning areas, or to enable fish
downstream access to known spawning areas and upstream return
after spawning.
2) Population "enhancement". Reopening or reestablishing historic
areas of river enabling adult fish to spawn; or enabling fish to
spawn downstream of the barrier and return upstream after
spawning. To be used if this biologically benefited the squawfish
population, i.e., if it contributed significantly to the total
reproductive success of the population.
Fish passageways, then, should only be seriously considered when it
can be demonstrated that at least one of the above items will benefit
the population.
4. Biological problems using a fish passageway:
1) If the instream barrier does not have a spillway feature,
downstream movement of fish of all size classes would depend on
the fish's ability to use the fish passageway to gain downstream
access. Fish moving downstream originating from upstream reaches
that have to pass through the reservoir may have difficulty in
locating the fish passageway or may never locate the passageway
and may become reservoir residents. In instances where a
reservoir exists upstream of the instream barrier, fish that
successfully use a fish passageway may become disoriented in the
reservoir and may never continue to move upstream, may become full
time residents in the reservoir and may become "biologically"
isolated from the population. An example of this is if either the
Juniper or Cross Mountain Dam projects on the Yampa River are
constructed. During the non-spawning period, adult squawfish
occupy areas above the proposed site for Cross Mountain Dam, and
above and within the proposed site for Juniper Dam. During the
spawning period, adult squawfish now migrate downstream to a
confirmed spawning area in Yampa Canyon and return upstream
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