EPA's Vessel General Permit and Small Vessel General

Most of the chum within this ESU return to northern tributaries of the Columbia River (in
Washington State), primarily the Grays River, in areas immediately below Bonneville Dam, and
in smaller numbers under the I-205 bridge near Vancouver. Chum populations that formerly
occupied tributaries on the south bank of the Columbia (in Oregon) are considered extirpated or
nearly so. Observers have documented spawning over multiple years in the mainstem Columbia
River, near McCord Creek and Multnomah Falls in Oregon, although the number of spawners in
these areas are generally quite low (McElhany et al. 2007).
Status and Trends
NMFS listed Columbia River chum salmon as threatened on March 25, 1999, and reaffirmed
their threatened status on June 28, 2005 (71 FR 37160). Chum salmon in the Columbia River
once numbered in the hundreds of thousands of adults and were reported in almost every river in
the Lower Columbia River basin, but by the 1950s most runs disappeared (Rich 1942, Marr
1943, Fulton 1970). The total number of chum salmon returning to the Columbia River in the
last 50 years has averaged a few thousand per year, with returns limited to a very restricted
portion of the historical range. Significant spawning occurs in only two of the 16 historical
populations, meaning that 88% of the historical populations are extirpated, or nearly so (Good et
al., 2005). The two remaining populations are the Grays River and the lower Columbia Gorge
tributaries (Good et al. 2005). Both long- and short-term trends for Grays River abundance are
negative, but the current trend in abundance for the lower Columbia Gorge tributaries is slightly
positive. Chum salmon appear to be extirpated from the Oregon portion of this ESU. In 2000,
ODFW conducted surveys to determine the abundance and distribution of chum salmon in the
Columbia River, and out of 30 sites surveyed, only one chum salmon was observed.
Few Columbia River chum salmon have been observed in tributaries between The Dalles and
Bonneville dams. Surveys of the White Salmon River in 2002 found one male and one female
carcass, with no evidence of spawning (Ehlke and Keller 2003). Chum salmon were not
observed in any upper Columbia Gorge tributaries during the 2003 and 2004 spawning ground
surveys. Finally, most Columbia River chum populations have been functionally extirpated or
are presently at very low abundance levels.
Historically, the Columbia River chum salmon supported a large commercial fishery in the first
half of this century which landed more than 500,000 fish per year as recently as 1942.
Commercial catches declined beginning in the mid-1950s, and in later years rarely exceeded
2,000 per year (Good et al. 2005). During the 1980s and 1990s, the combined abundance of
natural spawners for the lower Columbia Gorge, Washougal and Grays River populations was
below 4,000 adults. In 2002, however, the abundance of natural spawners exhibited a substantial
increase at several locations (estimate of natural spawners is approximately 20,000 adults) (Good
et al. 2005). The cause of this dramatic increase in abundance is unknown. However, long- and
short-term productivity trends for populations are at or below replacement. The loss of offchannel
habitat and the extirpation of approximately 17 historical populations increase this
species’ vulnerability to environmental variability and catastrophic events. Overall, the
populations that remain have low abundance, limited distribution, and poor connectivity (Good
et al. 2005).
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