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

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-~-: ~ ~ Observations were made during the treatment on the reaction
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_ of fish to rotenone. A high bank on the river's west shore, about
''two miles above station #4, provided an excellent vantage point for
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such observations. Prior to rotenone infusion, a school of large
.carp was noticed moving slowly about the deep pool at the base of
the high bank. When the rotenone arrived, as evidenced by the
===-:appearance of distressed fish in. the main current, the carp became
restless and suddenly headed downstream. Immediately prior to,
and for a short time after, arrival of the rotenone, numerous
schools of large fish were seen moving swiftly downstream. Moat
of these fish were large suckers and carp from upstream areas.
The arrival of the rotenone was marked by the sudden appear-
-ante, at the water's surface, of scattered whitefish which thrashed
-about in great distress.. The sequence of appearance of each species
- after exposure to the rotenone is given in Table 3. Various size
groups of different species seemed to pass by in bunches possibly
indicating. differences in the sensitivity of different size and age
groups to the toxicant.
Different species reacted to the rotenone in different ways.
As mentioned before, many fish tried to escape downstream; others
moved into uncontaminated backwaters and springs. When exposed
to the rotenone, some fish, especially whitefish., reacted violently
~by surfacing and splashing around. Others reacted by swimming
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