9544

• UCREFRP Catalog Number: 9544
• Author: Collins, K., P. and D. K. Shiozawa.
• Title: The Effects of Fish Predation on Backwater Invertebrate Communities of the Green River, Utah.
• USFW Year: 1994.
• USFW - Doc Type: Provo, UT.
• Copyright Material: NO

ABSTRACT
The role of fish predation on the structure of invertebrate communities in
backwater habitats of the Green River, a large river in eastern Utah, was examined by
placing a series of complete, partial, and no fish exclosures in backwater habitats and
sampling benthic and planktonic communities periodically through the summer. The
taxa showing the greatest direct effects from fish predation were the chironomid genus
Tan us, the corixidae, and the planktonic adult copepoda. The benthic densities of
the naupliar and copepodite stages of copepods showed a negative effect of
diminished fish numbers, probably the result of increased levels of corixidae and
Tanypus, which are known to prey on benthic organisms. This study indicates that
backwater fishes can significantly impact their resources, and coupled with observed
spatial overlap, suggest that Colorado squawfish Ptychocheilus lucius may be suffering
from resource competition during their post-larval stage. More research is necessary
to determine if this is the case.
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