Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Endangered Suckers: Environmental Baseline for Suckers
Tule Lake
Much like UKL, Tule Lake is a hypereutrophic water body that experiences poor
water quality during summer months, characterized by high water temperature
and pH, low DO, elevated unionized ammonia and nutrient concentration, and
intense growth phytoplankton. One difference between Tule Lake and UKL is the
fact that filamentous green algae dominate the phytoplankton community within
Tule Lake rather than AFA. Because Tule Lake is shallow and nutrients are
abundant, aquatic vegetation and phytoplankton are very productive, which
causes a large variation in the levels of DO and pH.
Tule Lake experiences extremely poor water quality on a seasonal basis during
summer months with water temperature exceeding 25ºC, pH exceeding 10 units,
and DO concentrations below 4 mg/L. Water quality conditions in Tule Lake,
and the mechanisms affecting water quality, are similar to those observed in the
UKL watershed. See the watershed alterations, water temperature, nutrient
loading, and agal productivity discussions in the UKL watershed section for more
detail.
C. Drastically Reduced Adult Populations
See discussion in Sucker Description, Life History, Habitat, Distribution, and
Abundance: Sucker Distribution and Habitat section.
D. Overharvesting by Sport and Commercial Fishering
Historically, the Klamath Tribes on UKL, its tributaries, and the Lost River used
Lost River and shortnose suckers for a subsistence fishery. From the 1960s until
1987, a popular sport snag fishery harvested spawning adult suckers mostly on the
Sprague and Williamson rivers and shoreline spawning areas of UKL (Andreasen
1975, Bienz and Ziller 1987). Over this period, the annual harvest of fish on the
Sprague and Williamson rivers declined 95 percent from about 12,500 to 680. In
addition, several spawning groups at Barkley Springs, Harriman Springs, Odessa
Springs, and other small springs along the eastern shoreline of UKL were
extirpated (Perkins et al. 2000 Water Quality, Reclamation 2001).
On the Lost River, spring sucker runs were relied upon by not only Native
Americans but also local settlers for both food consumption and livestock feed
(Coots 1965, Howe 1968). A cannery was established and other commercial
operations processed the suckers into oil, dried fish, and other products (USFWS
1993 Sucker).
Harvest of adult suckers was very detrimental to the UKL sucker populations,
which were already negatively affected by loss of spawning and rearing habitat
and poor water quality (Reclamation 2001). Several shoreline spawning groups
likely were extirpated by removing reproducing adults from the population. The
threat of overharvesting adult suckers has essentially been removed with the
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