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Effects of temperature, flow, and disturbance on adult spring-run chinook salmon
Elizabeth A. Campbell, University of California, Davis
Peter B. Moyle, University of California, Davis
Water Resources Center Technical Completion Report no. W-764
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ABSTRACT: Spring-run chinook salmon (Oncorhynchus tshawytscha) have an
unusual life history pattern in that they move into their
spawning streams in the spring, hold there all summer in deep
pools, and then spawn in the fall. Populations in the
Sacramento-San Joaquin and Klamath-Trinity drainages have
declined dramatically in recent years perhaps due to their
exceptional vulnerability to the negative effects of water
diversions (e.g. low flows/high temperatures) and human
disturbances in their stream habitat. We examined the limits of
pool holding capacity under varying conditions of temperature,
flow, and human use primarily in a 2.3 km study stretch in the
upper reaches of Deer Creek (Tehama County) during 1991.
We found some evidence that spring-run chinook salmon
continually move upstream over the summer. However, pool depth
also affected the presence of adult salmon. The number of salmon
counted reached an asymptote in many pools over the summer,
suggesting that pools have a limited holding capacity. Human
rafting activity caused an increase in salmon movement in pools,
and may stress salmon if it is a common activity. We documented
substantial evidence of possible harassment and poaching of
salmon in a 2.3 km study stretch of Deer Creek during 1991. This
evidence included the presence of heavy line and treble hooks in
pools containing adult salmon, and we even observed people with
snorkeling equipment trying to capture adult salmon with a
dipnet. Estimated spawning success was about 50-60% in Butte Creek in 1989 and Deer Creek in 1990 and 1991.
SUGGESTED CITATION:
Elizabeth A. Campbell and Peter B. Moyle,
"Effects of temperature, flow, and disturbance on adult spring-run chinook salmon"
(August 31, 1992).
University of California Water Resources Center.
Technical Completion Reports.
Paper 764.
http://repositories.cdlib.org/wrc/tcr/764
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