Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

Land use data indicate that the Columbia River chum salmon may be at risk of pesticide
exposure. In addition to general uses, registered 24(c) uses in Oregon include carbofuran
application to potatoes, nursery stock, sugar beets, and watermelons. The locations of highpesticide
use areas and the preferential use of river-edge habitat by chum salmon indicate that the
species is at risk of pesticide exposure. The developed area surrounding the cities of Portland
and Vancouver occurs along the migratory route of the Lower Gorge chum.
Columbia River chum salmon fry emerge between March and May and emigrate shortly
thereafter to nearshore estuarine environments (Salo 1991). This is in sharp contrast to other
salmonid behavior and indicates that chum salmon are less dependent on freshwater conditions
for survival. After emergence, juvenile Columbia River chum salmon spend around 24 days
feeding in the estuary. Adults return to spawn in the lower reaches of the Columbia River
between the ages of two and five from mid-October through December. An average of ten days
is spent in the freshwater by the spawning adults.
Given the life history of the Columbia River chum salmon, we expect that the proposed uses of
carbaryl, carbofuran, and methomyl pesticide products may lead to individual fitness level
consequences. We expect that exposure will occur, resulting in both acute lethality and sublethal
olfactory-mediated effects. However, we do not expect these effects to occur at a scale that
would have population-level effects. As chum fry are more precocious and quickly leave natal
streams, they are less reliant on the local invertebrate population. Given the life history of
Columbia River chum salmon, the risk to this species’ survival and recovery from the proposed
stressors of the action is low for carbaryl, carbofuran, and methomyl.
Hood Canal Summer­run Chum Salmon
This ESU includes 16 historical, naturally spawned populations of summer-run chum salmon in
Olympic Peninsula Rivers between Hood Canal and Dungeness Bay, Washington, as well as
eight artificial propagation programs. Of the historically existing populations, seven are believed
to be extirpated. Most of the extirpated populations occurred on the eastern side of the canal.
Only two of the remaining populations have long-term trends above replacement; long-term
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