EPA's Vessel General Permit and Small Vessel General

Status and Trends
Snake River sockeye salmon were originally listed as endangered in 1991 and retained that
classification when their status was reviewed on June 28, 2005 (70 FR 37160). The only extant
sockeye salmon population in the Snake River basin at the time of listing was that in Redfish
Lake, in the Stanley Basin (upper Salmon River drainage) of Idaho. Other lakes in the Snake
River basin historically supported sockeye salmon populations, including Wallowa Lake (Grande
Ronde River drainage, Oregon), Payette Lake (Payette River drainage, Idaho) and Warm Lake
(South Fork Salmon River drainage, Idaho; (Waples et al. 1997). These populations are now
considered extinct. Although kokanee, a resident form of O. nerka, occur in numerous lakes in
the Snake River basin, other lakes in the Stanley Basin, and sympatrically with sockeye in
Redfish Lake, resident O. nerka were not considered part of the species at the time of listing
(1991). Subsequent to the 1991 listing, a residual form of sockeye residing in Redfish Lake was
identified. The residuals are non-anadromous, completing their entire life cycle in fresh water,
but spawn at the same time and in the same location as anadromous sockeye salmon. In 1993,
NMFS determined that residual sockeye salmon in Redfish Lake were part of the Snake River
sockeye salmon. Also, artificially propagated sockeye salmon from the Redfish Lake Captive
Propagation program are considered part of this species (70 FR 37160; June 28, 2005).
Five lakes in the Stanley Basin historically contained sockeye salmon: Alturas, Pettit, Redfish,
Stanley and Yellowbelly (Bjornn et al. 1968). It is generally believed that adults were prevented
from returning to the Sawtooth Valley from 1910 to 1934 by Sunbeam Dam. Sunbeam Dam was
constructed on the Salmon River approximately 20 miles downstream of Redfish Lake. Whether
Sunbeam Dam was a complete barrier to adult migration remains unknown. It has been
hypothesized that some passage occurred while the dam was in place, allowing the Stanley Basin
population or populations to persist (Bjornn et al. 1968, Waples et al. 1991).
Adult returns to Redfish Lake during the period 1954 through 1966 ranged from 11 to 4,361 fish
(Bjornn 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 et al. 2005). Only 18 natural origin sockeye salmon have returned to the Stanley
Basin since 1987. During the fall of 1990, during the course of NMFS’ first status review on the
species, no fish were observed at Lower Granit Dam or entering the lake and only one fish was
observed in each of the two previous years. The first adult returns from the captive broodstock
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
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