Here's an abstract of something prepared by Nicholas Ling relative to some
contemplated applications in New Zealand. In Washington, as far as I know,
the Washington Department of
Fish and Wildlife oversees all applications of this piscicide.

Kelly McAllister
Washington Department of Fish and Wildlife
Olympia, Washington
Reply to: mcallisters4 at comcast.net

A B S T R A C T

Rotenone is a natural plant toxin used for centuries by indigenous peoples
of Southeast Asia and South America for the harvesting of fish for human
consumption.
It has been used as a commercial insecticide for more than 150 years and for
the management of fish populations since the 1930s. Fisheries management
uses include
eradication of pest fishes, quantifying populations, food web manipulation,
controlling fish diseases, and restoring water bodies for threatened
species. Rotenone is
considered one of the most environmentally benign toxicants available for
fisheries management. Fish are acutely sensitive to rotenone poisoning,
quickly absorbing
the toxin across the gill surface and dying within hours at concentrations
below 1 ppm, although individual species sensitivities vary widely. Aquatic
invertebrates are
generally less sensitive than fish, but it will cause significant collateral
loss of invertebrate fauna, although invertebrate populations quickly
recover. Humans and wildlife
are comparatively insensitive to rotenone, which provides a large safety
margin between concentrations required to kill fish and those that may prove
harmful to non-target,
non-aquatic organisms. Rotenone can be applied tostanding or flowing waters
as a generally dispersed toxicant, either in liquid or powdered form, or as
formulated baits
to target nuisance species. Rotenone is chemically unstable and breaks down
rapidly in the environment, yielding water soluble non-toxic products. It is
readily metabolised
to non-toxic excretable substances in the bodies of vertebrates receiving a
sub-lethal dose. Rotenone is not considered to be carcinogenic. Recent
experimental findings
linking it toParkinsonian effects seem unlikely to occur under normal uses.
Cost and availability limit the use of rotenone to relatively small water
bodies. This summary
reviews the toxicity of rotenone and its use in fisheries management. A
limited risk assessment for rotenone use in New Zealand is provided given
that its potential uses and
the sensitivities of indigenous species have not been determined.