EPA's Vessel General Permit and Small Vessel General

status as threatened on January 5, 2006 (71 FR 834). NMFS 1997 status review identified sharp
declines in the returns of naturally produced steelhead, beginning in the mid-1980s. At the time
nine of 13 trend indicators were in decline and the average abundance (geometric mean, 1992-
1996) for the DPS was 75,000 adult steelhead (8,900 naturally produced). Of this, about 7,000
were A-run adults, and about 1,400 were B-run adults (Busby et al. 1996).
The lack of data on adult spawning escapement for specific tributaries of the Snake River Basin
DPS continues to make a quantitative assessment of viability difficult. Available data indicate
that the overall long-term estimates of population trends have remained negative (Good et al.
2005). Annual return estimates are limited to counts of the aggregate return over Lower Granite
Dam, and spawner estimates for the Tucannon, Asotin, Grande Ronde and Imnaha Rivers. The
2001 return over Lower Granite Dam was substantially higher relative to the low levels seen in
the 1990s; the recent geometric 5-year mean abundance (Total escapement 106,175 with 14,768
natural returns) was approximately 28% of the interim recovery target level (52,000 natural
spawners) (Good et al. 2005). The 10-year average for natural-origin steelhead passing Lower
Granite Dam between 1996 and 2005 is 28,303 adults. Long-term trend estimates of the
population growth rate (λ) across the available data set was 0.998 assuming that natural returns
are produced only from natural-origin spawners, and 0.733 if both hatchery and wild spawners
are contributing to production equally (Good et al. 2005). The Snake River supports
approximately 63% of the total natural-origin production of steelhead in the Columbia River
Basin (Good et al. 2005).
Critical Habitat
NMFS designated critical habitat for Snake River steelhead on September 2, 2005 (70 FR
52630). Designated critical habitat includes the following subbasins: Hells Canyon, Imnaha
River, Lower Snake/Asotin, Upper Grand Ronde River, Wallowa River, Lower Grand Ronde,
Lower Snake/Tucannon, Upper Salmon, Pahsimeroi, Middle Salmon-Panther, Lemhi, Upper
Middle Fork Salmon, Lower Middle Fork Salmon, Middle Salmon, South Fork Salmon, Lower
Salmon, Little Salmon, Upper and Lower Selway, Lochsa, Middle and South Fork Clearwater,
and the Clearwater subbasins, and the Lower Snake/Columbia River corridor. These areas are
important for the species’ overall conservation by protecting quality growth, reproduction, and
feeding. The critical habitat designation for this DPS identifies primary constituent elements that
include sites necessary to support one or more steelhead life stages. Specific sites include
freshwater spawning sites, freshwater rearing sites, freshwater migration corridors, nearshore
marine habitat and estuarine areas. The physical or biological features that characterize these
sites include water quality and quantity, natural cover, forage, adequate passage conditions, and
floodplain connectivity. The final rule (70 FR 52630) lists the watersheds that comprise the
designated subbasins and any areas that are specifically excluded from the designation.
There are 289 watersheds within the range of Snake River steelhead. The total area of habitat
designated as critical includes about 8,000 miles of stream habitat. This designation includes the
stream channels within the designated stream reaches, and includes a lateral extent as defined by
the ordinary high water line. In areas where the ordinary high-water line is not defined the
lateral extent is defined as the bankfull elevation. Of the 289 fifth order streams reviewed in this
DPS, 231 received a high conservation value rating, 44 received a medium rating and 14
received a rating of low conservation value for the species. The lower Snake/Columbia
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