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

Habitats Occupied by Listed Salmonids
Listed salmonids occupy habitats that range from shallow, low flow freshwaters to open
reaches of the Pacific Ocean. All listed Pacific salmonid species use freshwater,
estuarine, and marine habitats. The temporal and spatial use of habitats by salmonids
depends on the species and the individuals’ life history and life stage (Table 47). Many
migrate hundreds or thousands of miles during their lifetime, increasing the likelihood
that they will come in contact with aquatic habitats contaminated with pesticides. Given
that all listed Pacific salmonid ESUs/DPSs use watersheds where the use of carbaryl,
carbofuran, and methomyl products is authorized, and these compounds are frequently
detected in watersheds where they are used (Gilliom, Barbash et al. 2006) we expect all
listed Pacific salmonid ESUs/DPSs will continue to be exposed to these compounds and
other stressors of the action.
Table 47. General life histories of Pacific salmonids.
Species General Life History Descriptions
(number of
listed
ESUs or
DPSs)
Spawning Migration Spawning Habitat Juvenile Rearing and Migration
Chinook Mature adults (usually Generally spawn in The alevin life stage primarily
(9) four to five years old) the middle and resides just below the gravel
enter rivers (spring upper reaches of surface until they approach or
through fall, depending on main stem rivers reach the fry stage. Immediately
run). Adults migrate and and larger tributary after leaving the gravel, fry swim-
spawn in river reaches streams. up and distribute to habitats that
extending from above the
provide refuge from fast currents
tidewater to as far as
and predators. Juveniles exhibit
1,200 miles from the sea.
two general life history types:
Chinook salmon migrate
Ocean-type fish migrate to sea in
and spawn in four distinct
their first year, usually within six
runs (spring, fall, summer,
months of hatching. Ocean-type
and winter). Chinook
juveniles may rear in the estuary
salmon are semelparous
for extended periods. Stream-
(can spawn only once).
type fish migrate to the sea in the
spring of their second year.
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