7058

• UCREFRP Catalog Number: 7058
• Author: Binns, N. A.
• Title: Effects of Rotenone Treatment on the Fauna of the Green River, Wyoming.
• USFW Year: 1966.
• USFW - Doc Type: Oregon State University,
• Copyright Material: NO

investi ational activities were
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concentrated on making population estimates, following the rotenone
~"_-movement, determining rotenone concentrations, and observing
the reactions of the- fauna to the toxicant.
Attempts to make fish population estimates were abandoned
after the first day, when the activities of crowds of people made
unbiased counts of fish along the banks impossible, Salvage by the
public greatly decreased the wastage of fish. At no time was there
any serious nuisance problem resulting from dead fish. Some in-
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formation was obtained by midstream drift counts made as the
rotenone moved past different points on the river. Observations
were also made at a few isolated locations which had not been
disturbed by the public. The results of these counts are presented
in Table 2. This table shows that Cottus bairdi was more common
in section II than was previously suspected. A brief, premature,
release of rotenone from station #1 was made on the evening prior
to the scheduled start. Because of this release, many trout were
killed before the main treatment and were removed by the public
before the count was made near the field bioassay site, thus inter-
ferring with the estimation of the trout population. Observations
,revealed marked dominance of whitefish in the fish population of
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