Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Coho Salmon: Environmental Baseline
Table 3-13. Projected exploitation rate on Rogue and Klamath River Hatchery-origin
coho salmon, 2002 to 2006.
Year
Projected Exploitation Rate on Rogue
and Klamath River Hatchery-origin
Coho Salmon
Source
2002 7.7 percent p. III-13, PFMC 2003
2003 7.7 percent p. 66, PFMC 2004
2004 7.7 percent p. 67, PFMC 2005
2005 7.7 percent p. 70, PFMC 2006
2006 5.2 percent p. 67, PFMC 2007
Average
7.2 percent
Direct harvest of coho salmon within the Klamath River Basin was terminated in
1994, with the exception of a limited harvest for subsistence and ceremonial
purposes of the Yurok, Hoopa Valley, and Karuk tribes. Recent harvests of coho
salmon in the Yurok Tribe fishery include 17 : 486 in 2002; 343 in 2003; and,
1,540 in 2004 (NMFS 2007). This harvest includes both hatchery-origin and
natural-origin coho salmon. NMFS (2002 BO) estimated the annual tribal harvest
of coho salmon to average less than 100 natural-origin coho salmon and less than
1 percent of the annual return of natural-origin coho salmon to the SONCC coho
salmon ESU.
Restrictions on recreational and commercial harvest of coho salmon since 1994
within the Klamath River Basin has undoubtedly had a beneficial effect on coho
salmon adult returns to SONCC coho salmon ESU streams (p. 363, NMFS 2005).
Mortality associated with incidental or illegal catch of natural-origin populations
within the SONCC coho salmon ESU is uncertain, but is believed to be low
(CDFG 2002).
Artificial Propagation
There are concerns that hatchery-origin fish may harm natural-origin populations.
Specifically, some fishery biologists are concerned that a preponderance of
hatchery-origin fish in a population could weaken that population’s ability to
respond to a diversity of environmental stresses and conditions. In addition, there
have been concerns that hatchery-origin fish could carry disease to the naturalorigin
population and reduce genetic variation.
17 Annual effort was not consistent between years.
178