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

Snake River Sockeye Salmon
The SR sockeye salmon ESU historically includes populations in five Idaho lakes as well as
artificially propagated sockeye salmon from the Redfish Lake Captive Broodstock Program.
Only one hatchery-sustained population remains and is found in Redfish Lake. This population
is listed as endangered and has an extremely high risk of extinction. Current smolt-to-adult
survival of sockeye originating from the Stanley Basin lakes is rarely greater than 0.3% (Hebdon,
Kline et al. 2004). No natural origin adults have returned to Redfish Lake to spawn since 1998;
the population is maintained entirely by propagation efforts. Around 30 fish of hatchery origin
return to spawn each year (FCRPS 2008).
The major threats to this ESU identified in the Status of Listed Resources and Environmental
Baseline sections include impaired tributary flow and passage, migration barriers, degraded
water quality, and hydromodification of the Columbia and Snake Rivers. Like the Ozette Lake
ESU, the SR sockeye occupy a relatively undeveloped area with very little cropland (Table 37)
However, the SR sockeye have the longest migration of any sockeye salmon, traveling 900 miles
inland. These waters are contaminated by drift and runoff from both agricultural and urban
areas. Exposure during migration likely adds to the low survivorship of smolts. The land use
and environmental data indicate that the SR sockeye may be exposed to carbaryl, carbofuran, and
methomyl during migration. Registered 24(c) uses within this ESU include carbofuran
application to potatoes and spinach grown for seed in Washington.
Historically, sockeye salmon entered the Columbia River system in June and July, and arrived at
Redfish Lake between August and September (FCRPS 2008). Spawning occurred in lakeshore
gravel and generally peaked in October. Fry emerged in the spring (April and May) then
migrated to open waters of the lake to feed. Juvenile sockeye remained in the lake for one to
three years before migrating through the Snake and Columbia Rivers to the ocean. Adult
sockeye spent two or three years in the open ocean before returning to Redfish Lake to spawn.
During adult and juvenile migrations the sockeye are at their greatest risk of exposure to the
stressors of the action. Sockeye salmon making the 900 mile journey each way pass along many
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