EPA's Vessel General Permit and Small Vessel General

educed by the loss of access to upper basins from tributary hydro development (i.e., Condit Dam
on the Big White Salmon River and Powerdale Dam on the Hood River). The diversity of
populations in all three areas has been eroded by large hatchery influences and periodically, low
effective population sizes.
Critical Habitat
NMFS has not designated critical habitat for Lower Columbia River coho salmon.
Southern Oregon/Northern California Coast Coho Salmon
Distribution and Description of the Listed Species
Southern Oregon/Northern California coast coho salmon consists of all naturally spawning
populations of coho salmon that reside below long-term, naturally impassible barriers in streams
between Punta Gorda, California and Cape Blanco, Oregon, as well as three artificial
propagation programs: the Cole Rivers Hatchery, Trinity River Hatchery and Iron Gate Hatchery
coho hatchery programs. The three major river systems supporting Southern Oregon – Northern
Coastal California coast coho are the Rogue, Klamath (including the Trinity), and Eel rivers.
Southern Oregon and Northern California coast coho immigrate to natal rivers in September or
October. River entry is much later south of the Klamath River Basin, occurring in November
and December, as well as in basins south of the Klamath River to the Mattole River, California.
River entry occurs from mid-December to mid-February in rivers farther south. Because
individuals enter rivers late, they spend much less time in the river. Coho salmon adults spawn
at age 3, spending just over 1 year in fresh water and a year and a half in the ocean.
Status and Trends
Southern Oregon/Northern California coast coho salmon were listed as threatened on May 7,
1997 (62 FR 24588); they retained that classification when their status was reviewed on June 28,
2005 (70 FR 37160). Southern Oregon/Northern California Coast coho salmon extend from
Cape Blanco in southern Oregon to Punta Gorda in northern California (Sandercock 1991). The
status of coho salmon coast-wide, including the Southern Oregon/Northern California Coast
coho salmon ESU, was formally assessed in 1995 (Sandercock 1991). Two subsequent status
review updates have been published by NMFS, one addressing all West Coast coho salmon
ESUs and a second specifically addressing the Oregon Coast Southern Oregon/Northern
California Coast coho salmon ESUs (NMFS 1996, 1997a). In the 1997 status update, estimates
of natural population abundance were based on very limited information. New data on
presence/absence in northern California streams that historically supported coho salmon were
even more disturbing than earlier results, indicating that a smaller percentage of streams
contained coho salmon compared to the percentage presence in an earlier study (Good et al.
2005). However, it was unclear whether these new data represented actual trends in local
extinctions or were biased by sampling effort.
Data on population abundance and trends are limited for the California portion of this ESU. No
regular estimates of natural spawner escapement are available. Historical point estimates of coho
salmon abundance for the early 1960s and mid-1980s suggest that statewide coho spawning
escapement in the 1940s ranged between 200,000 and 500,000 fish. Numbers declined to about
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