7332

• UCREFRP Catalog Number: 7332
• Author: Valdez, R. A., et al.
• Title: Final Report Habitat Suitability Index Curves for Endangered Fishes of the Upper Colorado River Basin.
• USFW Year: 1987.
• USFW - Doc Type: \
• Copyright Material: NO

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SUMMARY

This document presents Habi tat Sui tabili ty Index curves and
documentation for three species of endangered fishes in the Upper Colorado
River Basin: Colorado squawfish, humpback chub, and razorback sucker. The
curves and pertinent documentation are presented together under Task F of this
report to facili tate access and use. The curves are formatted with curve
coordinates such that they are easily integrated with the PHABSIM models of the
Instream Flow Incremental Methodology, for generating habitat weighted useable
area.

This document is organized into six sections by project task. Each
section identifies the task objective, methods, and results.

Task A - Database Assimilation: describes the database assimilated, as
well as summary tables and narratives that present habitat data for the three
target fishes. Also summarizes past studies in which habitat curves were
developed for thel?e species and presents the resultant curves. The da.ta
assimilated spanned a period of 23 years, from 1964 through 1986, and included
collections of 17 principal investigators in 99 studies.

Task B - Workshop U: describes the procedures used to conduct a
workshop in which species experts decided, by consensus, on the data to use for
developing HSI curves, and methods of analysis and curve development.
Statistical tests, partitioning, and pooling of data are described. The week-
long workshop was attended by 17 people, including 5 species experts, 9
participants, and 3 BIO/WEST organizers. A total of 291 data partitions were
identified for analysis and possible curve development.

Task C - Draft Report With preliminary HSI CUrves: describes the
resul ts of statistical tests to pool or partition data and techniques for
generating HSI curves. Preliminary curves, included in the draft report for
consideration in Workshop #2 (Task D), are described but not presented in this
document. The 291 data partitions identified in Task B were reduced to 56 sets
of preliminary curves following statistical analyses specified by the experts
in Workshop #1.

Task D - Workshop #2: describes the procedures used to conduct Workshop
#2 in which species experts examined preliminary curves and statistical
analyses to arrive at final HSI curves. Of the 56 preliminary curve sets, the
experts decided on 18 sets of final curves, applied to 32 size categories or
life functions of the three target species. Of the 18 final curve sets, the
experts recommended applying only 12 sets because of additional concerns for
modeling certain habitat types being used by the fish. The criteria for this
determination was expressed in a "General Habitat Constraint".

Task E - Draft Final Report: contains final Habitat Suitability Index
curves as determined by the experts, associated draft documentation, and
constraints for use.

Task F - Final Report: contains final Habitat Suitability Index curves
as determined by the experts, associated documentation, and constraints for
use. Contains a comparison of curves from previous studies with current HSI
curves, a discussion of project results, and recommendations.o
v