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

Adult returns to Redfish Lake during the period 1954 through 1966 ranged from 11 to
4,361 fish (Bjornn, Craddock et al. 1968). Sockeye salmon in Alturas Lake were
extirpated in the early 1900s as a result of irrigation diversions, although residual sockeye
may still exist in the lake (Chapman and Witty 1993). From 1955 to 1965, the Idaho
Department of Fish and Game eradicated sockeye salmon from Pettit, Stanley, and
Yellowbelly lakes, and built permanent structures on each of the lake outlets that
prevented re-entry of anadromous sockeye salmon (Chapman and Witty 1993). In 1985,
1986, and 1987, 11, 29, and 16 sockeye, respectively, were counted at the Redfish Lake
weir (Good, Waples et al. 2005). Only 18 natural origin sockeye salmon have returned to
the Stanley Basin since 1987. The first adult returns from the captive brood stock
program returned to the Stanley Basin in 1999. From 1999 through 2005, a total of 345
captive brood program adults that had migrated to the ocean returned to the Stanley
Basin.
Recent annual abundances of natural origin sockeye salmon in the Stanley Basin have
been extremely low. No natural origin anadromous adults have returned since 1998 and
the abundance of residual sockeye salmon in Redfish Lake is unknown. This species is
entirely supported by adults produced through the captive propagation program at the
present time. Current smolt-to-adult survival of sockeye originating from the Stanley
Basin lakes is rarely greater than 0.3% (Hebdon, Kline et al. 2004). Based on current
abundance and productivity information, the SR sockeye salmon ESU does not meet the
ESU-level viability criteria (non-negligible risk of extinction over a 100-year time
period).
Critical Habitat
Critical habitat for these salmon was designated on December 28, 1993 (58 FR 68543).
Designated habitats encompasses the waters, waterway bottoms, and adjacent riparian
zones of specified lakes and river reaches in the Columbia River that are or were
accessible to listed SR salmon (except reaches above impassable natural falls, and
Dworshak and Hells Canyon Dams). Adjacent riparian zones are defined as those areas
within a horizontal distance of 300 ft from the normal line of high water of a stream
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