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

not been determined. Although the number of adult spring-run Chinook salmon crossing
Willamette Falls is in the same range (about 20,000 to 70,000 adults) it has been for the
last 50 years, a large fraction of these are hatchery produced. Of concern is that a
majority of the spawning habitat and approximately 30 to 40% of total historical habitat
are no longer accessible because of dams (Good, Waples et al. 2005).
Critical Habitat
Critical habitat was designated for this species on September 2, 2005 (70 FR 52630).
Designated critical habitat includes all Columbia River estuarine areas and river reaches
proceeding upstream to the confluence with the Willamette River as well as specific
stream reaches in a number of subbasins. The critical habitat designation for this ESU
also identifies PCEs that include sites necessary to support one or more Chinook salmon
life stages. Specific sites include freshwater spawning and rearing sites, freshwater
migration corridors. The physical or biological features that characterize these sites
include water quality and quantity, natural cover, forage, adequate passage conditions,
and floodplain connectivity. Of 65 subbasins reviewed in NMFS’ assessment of critical
habitat for the UWR Chinook salmon ESU, 19 subbasins were rated as having a medium
conservation value, 19 were rated as low, and the remaining subbasins (27), were rated as
having a high conservation value to UWR Chinook salmon. Federal lands were generally
rated as having high conservation value to the species' spawning and rearing. Factors
contributing to the downward trends in this ESU include: (1) Reduced access to
spawning/rearing habitat in tributaries, (2) hatchery impacts, (3) altered water quality and
temperature in tributaries, (4) altered stream flow in tributaries, and (5) lost/degraded
floodplain connectivity and lowland stream habitat.
Chum Salmon
Description of the Species
Chum salmon has the widest natural geographic and spawning distribution of any Pacific
salmonid because its range extends farther along the shores of the Arctic Ocean than
other salmonids. Chum salmon have been documented to spawn from Korea and the
Japanese island of Honshu, east around the rim of the North Pacific Ocean to Monterey
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