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

surface and ground water and degrade water quality in the freshwater, estuarine, and
coastal ecosystems throughout the Pacific Northwest.
Upper Willamette River Chinook Salmon
Distribution
Upper Willamette River (UWR) Chinook salmon occupy the Willamette River and
tributaries upstream of Willamette Falls (Figure 15). In the past, this ESU included
sizable numbers of spawning salmon in the Santiam River, the middle fork of the
Willamette River, and the McKenzie River, as well as smaller numbers in the Molalla
River, Calapooia River, and Albiqua Creek. Historically, access above Willamette Falls
was restricted to the spring when flows were high. In autumn, low flows prevented fish
from ascending past the falls. The UWR Chinook salmon are one of the most genetically
distinct Chinook salmon groups in the Columbia River Basin. Fall-run Chinook salmon
spawn in the Upper Willamette but are not considered part of the species because they are
not native. None of the hatchery populations in the Willamette River were listed
although five spring-run hatchery stocks were included in the species’ listing. UWR
Chinook salmon migrate far north and are caught incidentally in ocean fisheries,
particularly off southeast Alaska and northern Canada, and in spring season fisheries in
the mainstem Columbia and Willamette Rivers. Table 12 identifies populations within
the UWR Chinook salmon ESU, their abundances, and hatchery input
Table 12. UWR Chinook salmon populations, abundances, and hatchery contributions
(Good, Waples et al. 2005). Note: rpm denotes redds per mile
Current Populations
Historical
Abundance
Most Recent
Spawner
Abundance
Hatchery
Abundance
Contributions
Clackamas River Unknown 2,910 64%
Molalla River Unknown 52 redds >93%
North Santiam River Unknown ~ 7.1 rpm >95%
South Santiam River Unknown 982 redds >84%
Calapooia River Unknown 16 redds 100%
McKenzie River Unknown ~2,470 26%
Middle Fork Willamette River Unknown 235 redds >39%
Upper Fork Willamette River Unknown Unknown Unknown
Total >70,000 ~9,700 Mostly hatchery
.
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