7815

• UCREFRP Catalog Number: 7815
• Author: U.S. Fish and Wildlife Service.
• Title: Strategy for Determination of Habitat Requirements for the Rare Fishes of the Upper Colorado River Basin.
• USFW Year: 1988.
• USFW - Doc Type: \
• Copyright Material: NO

Until recently, emphasis has been placed on use of the Physical Habitat
Simulation System (PHABSIM) for developing habitat versus streamflow
relationships in the Basin. PHABSIM simulates depth, velocity, and substrate
but does not consider other variables which may be equally or more important to
species' well-being (such as other physical habitat variables, water quality,
temperature, food supply, or biotic interactions). Recovery of the rare fishes
is likely unobtainable until the key limiting factors are identified and
abated.
In summary, based on the requirements of the Recovery Implementation Program,
the issues and concerns identified by the Service, the responsibilities of the
Service and Implementation Committees, and the need to ensure that recommended
measures will protect the species, a strategy is outlined-for the determination
of habitat requirements for the rare fishes of the Basin. The approach is
flexible in that it provides a framework upon which to build. Such a framework
can be used for individual river reaches or entire river systems. Empirical
relationships (combined with mathematical models for extrapolation) are used
where possible; peer review and varying amounts of professional judgment are
required throughout. Assumptions and data are documented to allow for a clear
understanding of the logic and thought processes.
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