Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Endangered Suckers: Environmental Baseline for Suckers
Table 2-5. Sediment accumulation rate from UKL sediment core analysis.
Year Sediment Accumulation
Rate (g/m 2 /year)
1880 18
1900 20
1920 20
1940 30
1960 40
1980 60
1995 120
Source: Eilers et al. 2001
Water Temperature
Temperature plays a major role in water quality by directly causing stress to fish,
as well as exacerbating other processes affecting water quality such as:
• DO. Temperature directly influences DO solubility as well as accelerate
oxygen consuming microbial processes (Biochemical Oxygen Demand
[BOD] and Sediment Oxygen Demand [SOD]).
• AFA production. Higher water temperature stimulates amplified AFA
production leading to further water quality degradation. The greatest
density of AFA coincides with warmer water temperature (Wood et al.
2006).
Water temperature within UKL annually exceeds 25 degrees Celcius (ºC) during
summer months, typically reaching a maximum in late July to early August.
These excessively warm water temperatures can be stressful and at times leathal
to fishes within UKL. The Oregon Department of Environmental Quality
(ODEQ) has identified nearly 25 stream segments flowing into UKL as
“temperature limited” (ODEQ 1998). Increased temperatures are symptomatic of
degraded stream conditions resulting from increased sedimentation, loss of
riparian vegetation, and channel modifications associated with logging, intensive
grazing, flow reductions, and agricultural activities. However, air temperature
and solar radiation likely have a greater effect on increasing water temperature of
UKL than tributary inflows under the current tributary hydrology.
Nutrient Loading
High nutrient loading promotes correspondingly high algae production, which, in
turn, modifies physical and chemical water quality characteristics that can directly
diminish the survival and production of fish populations. Accelerated phosphorus
loading is likely a key factor driving the massive AFA blooms that now dominate
UKL. ODEQ established a Total Maximum Daily Load (TMDL) for UKL in
2002 targeted at reduction of phosphorous as a means to reduce AFA production
and improve water quality conditions such that water quality criteria would be
attained. Through modeling and analysis efforts, ODEQ (2002) determined that
phosphorous reduction would be the most effective means of improving water
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