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

circles, at the same time making convulsive, shivering body
This reaction was followed by vigorous diving and
__
ing as the fish moved downstream. Prolonged exposure to
62
°~e oxicant resulted in many fish moving toward shore, a common
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:,,t+~~~onse of the suckers (Figure 21);, Other fish ceased atruggli~g
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~d began to drift downstream with the current as though stunned.,
T?~i:s was a characteristic reaction of carp which drifted slowly,
downstream, apparently dazed, but still responsive to sight stimuli.
As the duration of toxicant exposure increased, greater num-
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_ bcra of fish were observed dead or dying along the bank or drifting
downstream with the current. Great numbers of dead fish rolled.-
ax-.d tumbled along with the. stream current.. After about three hbuxs
- n#_esposure to the toxicant, carp- in the quiet waters were unrespon-
give to stimulation and had often lost their equilibrium. By this
dime, only dead fish were to be seen in the main stream flow.
Large numbers of dead fish often accumulated just above each
rotenone introduction station. These fish were evidently escapees
trapped between the rotenone moving downstream and the rotenone
newly introduced.
Table 4 presents the predicted and observed arrival time of
the rotenone at some of the stations. Observations on fish held in
_ "live cages" are also given. The predicted arrival time was cal-
___ _.-_'_-culated from an estimated stream velocity of one mile per hour
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