EPA's Vessel General Permit and Small Vessel General

greater than 0.3% (Hebdon et al. 2004). The status of this ESU is extremely precarious, such
that there was unanimous consent among the biological review team members that the species
remains in danger of extinction (Good et al. 2005).
Critical Habitat
Critical habitat for these salmon was designated on December 28, 1993 (58 FR 68543), and
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 Snake River 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 feet from
the normal line of high water of a stream channel or from the shoreline of a standing body of
water. Designated critical habitat includes the Columbia River from a straight line connecting
the west end of the Clatsop jetty (Oregon side) and the west end of the Peacock jetty
(Washington side) and including all river reaches from the estuary upstream to the confluence of
the Snake River, and all Snake River reaches upstream to the confluence of the Salmon River; all
Salmon River reaches to Alturas Lake Creek; Stanley, Redfish, yellow Belly, Pettit, and Alturas
Lakes (including their inlet and outlet creeks); Alturas Lake Creek and that portion of Valley
Creek between Stanley Lake Creek and the Salmon River. Critical habitat also includes all river
lakes and reaches presently or historically accessible to Snake River sockeye salmon. These
habitats are critical for the conservation of the species because it provides spawning and juvenile
rearing habitat, areas for juvenile growth and development, and migration corridors for smolts to
the ocean and adults to spawning habitat from the Pacific Ocean. Limiting factors identified for
Snake River sockeye include: reduced tributary stream flow, impaired tributary passage and
blocks to migration, and mainstem Columbia River hydropower system mortality.
Steelhead
Description of the Species
Steelhead, the common name of the anadromous form of O. mykiss, are native to Pacific Coast
streams extending from Alaska south to northwestern Mexico (Moyle 1976a, NMFS 1997b).
The life history of this species varies considerably throughout its range. Generally, steelhead
comprise into two races: the stream-maturing type; and the ocean-maturing type.
Summer steelhead enter fresh water between May and October in the Pacific Northwest
(Nickelson et al. 1992, Busby et al. 1996). They require cool, deep holding pools during summer
and fall, prior to spawning (Nickelson et al. 1992). Summer steelhead migrate inland toward
spawning areas, overwinter in the larger rivers, resume migration in early spring to natal streams,
and then spawn in January and February (Barnhart 1986, Meehan and Bjornn 1991, Nickelson et
al. 1992). Winter steelhead enter fresh water between November and April in the Pacific
Northwest (Nickelson et al. 1992), migrate to spawning areas, and then spawn, generally in
April and May (Barnhart 1986). Some adults, however, do not enter some coastal streams until
spring, just before spawning (Meehan and Bjornn 1991).
In late spring, after emerging from the gravel, fry usually inhabit shallow water along banks of
perennial streams (Nickelson et al. 1992). Summer rearing takes place primarily in the faster
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