EPA's Vessel General Permit and Small Vessel General

to 3,714 while naturally produced steelhead declined from 450 to 358. Thus, the contribution of
naturally produced steelhead declined from 19% to only 9% of total escapement between the
1993 and 2001 estimates (Good et al. 2005).
The assumptions of the role that hatchery fish play in the overall productivity and health of the
DPS strongly influence estimates of population growth rates. Estimates based on the assumption
that hatchery fish contribute to natural production at the same rate as natural-origin spawners
consistently result in long-term population growth rates (expressed as λ) that are consistently
below 1 (Good et al. 2005). Under the assumption that hatchery fish do not contribute to natural
production, estimates of long term population growth rate suggest the population is growing.
Determining the actual contribution of hatchery fish to natural production is important for
understanding the true status of this DPS, particularly given that the proportion of naturally
produced steelhead to hatchery-origin steelhead continues to decline. The extremely low
replacement rate of naturally produced steelhead in this DPS is of concern.
The majority of the biological review team (54%) felt that this DPS warranted an “endangered”
listing due to the growth rate and productivity, and uncertainty over the contribution of hatchery
fish to natural production. NMFS, after convening a review of the artificial propagation
programs of the six hatcheries in the DPS concluded that the programs collectively mitigate the
immediacy of extinction risk in the DPS. Thus, NMFS listed the DPS as threatened rather than
threatened (71 FR 834). NMFS concluded that the hatchery programs have increased total
escapement and the distribution of spawning areas, and minimize the potential risks associated
with artificial propagation. However, the abundance and productivity of naturally spawned
steelhead remains a concern.
Critical Habitat
NMFS designated critical habitat for Upper Columbia River steelhead on September 2, 2005 (70
FR 52630). Designated critical habitat includes the following subbasins: Chief Joseph,
Okanogan, Similkameen, Methow, Upper Columbia/Entiat, Wenatchee, Lower Crab, and the
Upper Columbia/Priest Rapids subbasins, and the 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 42 watersheds within the range of Upper Columbia River steelhead. The total area of
habitat designated as critical includes about 1,250 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 42 watersheds reviewed in
NMFS' assessment of critical habitat for Upper Columbia River steelhead, three watersheds
received a low rating of conservation value, eight received a medium rating, and 31 received a
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