Biological Opinions - Bureau of Reclamation

Oregon Department of Fish and Wildlife requires scientific take permits that are reviewed to
ensure there is minimal impact to native fish populations.
7.10.6 Conclusions Regarding the Ability of the Action Area to Support LRS and SNS
Conservation
The recovery plan for the LRS and the SNS establishes a strategy that is intended to produce
healthy, self-sustaining populations of the LRS and the SNS within the action area by reducing
sucker mortality; restoring habitat, including sucker spawning, larval, and juvenile habitats; and
increasing connectivity between sucker spawning and rearing habitats (USFWS 2013).
Recovery also involves ameliorating the adverse effects of degraded water quality, disease, and
nonnative fish on LRS and SNS populations. The recovery goal is to produce naturally selfsustaining
populations that possess healthy long-term demographic traits and trends (USFWS
2013).
UKL is especially critical to the conservation of the LRS and the SNS because it provides the
most habitat and has the greatest variety of spawning sites. Currently, the largest population of
the LRS is found in UKL and its tributaries. It is possible that UKL supported the largest SNS
population, but its abundance there has decreased substantially from a decade ago (Hewitt et al.
2012). Even though the LRS and the SNS are dependent on UKL during nearly every life stage,
conditions in the lake are seasonally adverse due to poor water quality, algal toxins, and other
factors. Suckers stressed by poor water quality are more vulnerable to disease, predators, and
entrainment. There is also a variety of parasites in the lake that reduce sucker survival. Habitat
conditions also have been degraded by loss of wetlands. Substantial entrainment of larval and
juvenile suckers occurs at the outlet of UKL. The nearly universal disappearance of juvenile
suckers from UKL beginning in August and extending into October (Simon et al. 2011), likely in
response to the synergistic effects of the above factors, has precluded adequate recruitment into
the adult populations of the LRS and the SNS in UKL in over a decade; neither the LRS or the
SNS populations in UKL exhibit normal population demographic patterns and are not selfsustaining.
This lack of recruitment is increasing the risk for a collapse and extirpation of the
LRS and the SNS from UKL as the older adult populations continue to age and die.
Keno Reservoir and the downstream hydroelectric reservoirs are highly altered systems that
currently support small sucker populations, mostly of the SNS. All of these areas provide
recovery benefits by adding redundancy, but currently they do not support self-sustaining
populations because of habitat limitations. Because Keno Reservoir is downstream of UKL, and
large numbers of suckers disperse there from upstream, it has the potential to provide rearing
habitat for suckers that ultimately could migrate back to UKL. Nevertheless, habitat and water
quality conditions in the Keno Reservoir are seasonally adverse, and are unlikely to change
substantially over the next decade.
Climate change is having a small but measureable effect over the entire Klamath River Basin.
Air and water temperatures are increasing, and inflows to UKL are diminishing, at least during
the summer to early winter period. The effects of climate change on air and water temperatures
and on the magnitude, duration, and timing of inflows to UKL are expected to get more severe in
the future (Flint and Flint 2011, Markstrom et al. 2011).
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