EPA's Vessel General Permit and Small Vessel General

support one or more Chinook salmon 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 critical habitat designation (70 FR 52488) contains additional details on the
sub-areas that are included as part of this designation, and the areas that were excluded from
designation.
In total, California Coastal Chinook salmon occupy 45 watersheds (freshwater and estuarine).
The total area of habitat designated as critical includes about 1,500 miles of stream habitat and
about 25 square miles of estuarine habitat, mostly within Humboldt Bay. 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. In estuarine areas the lateral extent
is defined by the extreme high water because extreme high tide areas encompass those areas
typically inundated by water and regularly occupied by juvenile salmon during the spring and
summer, when they are migrating in the nearshore zone and relying on cover and refuge qualities
provided by these habitats, and while they are foraging. Of the 45 watershed reviewed in NMFS'
assessment of critical habitat for California Coastal Chinook salmon, eight watersheds received a
low rating of conservation value, 10 received a medium rating, and 27 received a high rating of
conservation value for the species.
Critical habitat in this ESU consists of limited quantity and quality summer and winter rearing
habitat, as well as marginal spawning habitat. Compared to historical conditions, there are fewer
pools, limited cover, and reduced habitat complexity. The limited instream cover that does exist
is provided mainly by large cobble and overhanging vegetation. Instream large woody debris,
needed for foraging sites, cover and velocity refuges is especially lacking in most of the streams
throughout the basin. NMFS has determined that these degraded habitat conditions are, in part,
the result of many human-induced factors including dam construction, agricultural and mining
activities, urbanization, stream channelization, water diversion and logging.
Central Valley Spring-Run Chinook Salmon
Distribution and Description of the Listed Species
The Central Valley spring-run Chinook salmon ESU includes all naturally spawned populations
of spring-run Chinook salmon in the Sacramento River and its tributaries in California. This
ESU includes one artificial propagation program. Central Valley spring-run Chinook salmon
ESU includes Chinook salmon entering the Sacramento River from March to July and spawning
from late August through early October, with a peak in September. Spring-run fish in the
Sacramento River exhibit an ocean-type life history, emigrating as fry, sub-yearlings and
yearlings. Central Valley spring-run Chinook salmon require cool freshwater while they mature
over the summer.
Status and Trends
NMFS originally listed Central Valley spring-run Chinook salmon as threatened on September
16, 1999 (64 FR 50393), a classification this species retained on June 28, 2005 (70 FR 37160).
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