Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

extinction,” with the remaining 19% of votes for “likely to become endangered. This was
based on extremely strong concern for abundance, productivity, and spatial concern (as
per the risk matrix); diversity was also of concern. The BRT also expressed concern
about the lack of data on the SC steelhead DPS, including uncertainty on the
metapopulation dynamics in the southern part of the DPS’s range and the fish’s nearly
complete extirpation from the southern part of the range.
Critical Habitat
Critical habitat was designated for this species on September 2, 2005. The designation
identifies PCEs that include sites necessary to support one or more steelhead life stages.
These sites contain the physical or biological features essential for the species
conservation. Specific sites include freshwater spawning sites, freshwater rearing sites,
freshwater migration corridors, and estuarine areas. The physical or biological features
that characterize these sites include water quantity, depth, and velocity, shelter, cover,
living space and passage conditions.
Upper Columbia River Steelhead
Distribution
UCR steelhead occupy the Columbia River Basin upstream from the Yakima River,
Washington, to the border between the U.S. and Canada (Figure 33). This area includes
the Wenatchee, Entiat, and Okanogan Rivers. All UCR steelhead are summer steelhead.
Steelhead primarily use streams of this region that drain the northern Cascade Mountains
of Washington State. This species includes hatchery populations of summer steelhead
from the Wells Hatchery because it probably retains the genetic resources of steelhead
populations that once occurred above the Grand Coulee Dam. This species does not
include the Skamania Hatchery stock because of its non-native genetic heritage.
Abundance estimates of returning naturally produced UCR steelhead have been based on
extrapolations from mainstem dam counts and associated sampling information (e.g.,
hatchery/wild fraction, age composition). The natural component of the annual steelhead
run over Priest Rapids Dam increased from an average of 1,040 (1992-1996),
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