EPA's Vessel General Permit and Small Vessel General

in Oregon coastal streams south of the Columbia River and north of Cape Blanco (63 FR 42587;
August 1998). One hatchery population, the Cow Creek hatchery coho salmon, is considered
part of the ESU.
Status and Trends
The Oregon coast coho salmon ESU was listed as a threatened species under the ESA on
February 11, 2008 (73 FR 7816), the conclusion to a 13-year history of court cases. The most
recent NMFS status review for the Oregon Coast coho ESU was conducted by the biological
review team in 2003, which assessed data through 2002. The abundance and productivity of
Oregon Coast coho since the previous status review represented some of the best and worst years
on record (Sandercock 1991). Yearly adult returns for the Oregon Coast coho ESU were over
160,000 natural spawners in 2001 and over 260,000 in 2002, far exceeding the abundance
observed for the past several decades (Good et al. 2005). These increases in spawner abundance
in 2000 to 2002 followed three consecutive brood years (the 1994 to 1996 brood years returning
in 1997 to 1999, respectively) exhibiting recruitment failure (recruitment failure is when a given
year class of natural spawners fails to replace itself when its offspring return to the spawning
grounds 3 years later). These 3 years of recruitment failure were the only such instances
observed thus far in the entire 55-year abundance time series for Oregon Coast coho salmon
(although comprehensive population-level survey data have only been available since 1980).
The 2000 to 2002 increases in natural spawner abundance occurred in many populations in the
northern portion of the ESU, which were the most depressed at the time of the last review
(Sandercock 1991). Although encouraged by the increase in spawner abundance in 2000 to
2002, the biological review team noted that the long-term trends in ESU productivity were still
negative due to the low abundances observed during the 1990s.
Since the biological review team convened, the total abundance of natural spawners in the
Oregon Coast coho ESU has declined each year (i.e., 2003 to 2006). The abundance of total
natural spawners in 2006 (111,025 spawners) was approximately 43 % of the recent peak
abundance in 2002 (255,372 spawners). In 2003, ESU-level productivity (evaluated in terms of
the number of spawning recruits resulting from spawners 3 years earlier) was above replacement,
and in 2004, productivity was approximately at replacement level. However, productivity was
below replacement in 2005 and 2006, and dropped to the lowest level since 1991 in 2006 (73 FR
7816).
Preliminary spawner survey data for 2007 (the average peak number of spawners per mile
observed during random coho spawning surveys in 41 streams) suggest that the 2007 to 2008
return of Oregon Coast coho is either (1) much reduced from abundance levels in 2006, or (2)
exhibiting delayed run timing from previous years. As of December 13, 2007, the average peak
number of spawners per mile was below 2006 levels in 38 of 41 surveyed streams (see ODFW
2007 in 73 FR 7816). It is possible that the timing of peak spawner abundance is delayed
relative to previous years, and that increased spawner abundance in late December and January
2008 will compensate for the low levels observed thus far.
The recent 5-year geometric mean abundance (2002 to 2006) of approximately 152,960 total
natural spawners remains well above that of a decade ago (approximately 52,845 from 1992 to
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