Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Coho Salmon: Coho Salmon Life History, Abundance, and Trends
the upper main stem Klamath River is equal or greater in some years to
contributions from the Shasta and Scott Rivers, which are critically important
populations to spatial distribution and diversity for the SONCC.coho salmon
ESU.
Table 3-9. Initial partitioning of the coho salmon Klamath River return to various reaches,
Klamath River Basin, 2002 to 2004. This information supports the general understanding
that little spawning is occurring in the main stem of the lower and middle Klamath River.
Reach 2002
Brood
2003
Brood
2004
Brood
Upper Main Stem Klamath River 4 % 1 % 1 %
Shasta River 4 % 2 % 2 %
Scott River 2 % 0 % 13 %
Upper Miscellaneous Tributaries 59 % 42 % 21 %
Middle Main Stem Klamath River 0 % 0 % 0 %
Salmon River 2 % 1 % 0 %
Middle Miscellaneous Tributaries 10 % 5 % 7 %
Lower Main Stem Klamath River 0 % 0 % 0 %
Trinity River 20 % 42 % 48 %
Lower Miscellaneous Tributaries 0 % 6 % 8%
Source: Table 11, p. 22, Cramer Fish Sciences 2006 Technical Memorandum 1.
A coarse-scale approach for estimating habitat potential for producing coho
salmon, known as Intrinsic Potential 11 , has been applied to the Klamath River
Basin (Agrawal et al. 2005). The analysis suggests that the greatest availability of
high quality coho salmon habitat prior to human development was located in the
Scott and Shasta River watersheds. The estimates of coho salmon spawning
distribution in Table 3-9 indicate that the Shasta River and Scott River sub-basins
are performing far below their pristine potential. Both sub-basins have been
substantially altered by human development and water diversions.
11 The Intrinsic Potential (IP) method was developed by Burnette (2001) and Burnette et al.
(2003).
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