8006

• UCREFRP Catalog Number: 8006
• Author: Hawkins, J. A., E. J. Wick and D. E. Jennings.
• Title: Icthyofauna of the Little Snake River, Colorado, 1994 - Final Report.
• USFW Year: 1997.
• USFW - Doc Type: Denver, CO.
• Copyright Material: NO

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estimate of species abundance and confirmed the paucity of nonnative species in
the Little Snake River. Estimated composition of one pool we sampled was 87%
native and 13% nonnative species.

The reasons for so few nonnative fishes compared to other Upper Basin
rivers are unknown but the extreme physical characteristics of the Little Snake
River may limit nonnative fish distribution and survival. The Little Snake River
provides an extremely variable and harsh environment for which most nonnative
fishes may not be well adapted. Physical processes that are extreme in the Little
Snake River include a high amplitude between peak and baseflow events, a very
turbid runoff, extremely low baseflows, and high amplitude of diel water
temperatures during baseflow.

Our understanding of tributaries in the Upper Basin is limited, yet their
contribution to the ecosystem and to endangered fish recovery may be significant
and therefore deserves further research and understanding. Tributaries like this
deserve study to assist us in understanding the influence of physical processes on
fish communities. Extreme conditions make the Little Snake River a valuable area
for use as a reference site to study the influence of geomorphology, flow,
sediment, and temperatures in structuring fish communities and possibly in
controlling undesirable nonnative fishes. Based on our present results and
observations we recommend the following:

1. Continue sampling the Little Snake River for endangered fishes to identify
their period of use and the potential significance of the Little Snake River in
their life history.

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