Our new Biological Assessment is out - Klamath Basin Crisis

Klamath Project Operations Biological Assessment
Endangered Suckers: Environmental Baseline for Suckers
Restoration efforts at the Williamson River Delta include reshaping the mouth of
the river through several levee breaches and channel reformation. The levee
breaches will divide the inflow from the Williamson River so that portions of the
total inflow will reach UKL through multiple mouths rather than the total inflow
arriving through the single, present-day mouth. Larval suckers carried to the lake
environment via the Williamson River will likely arrive through the future
multiple mouths. The distribution of larval suckers in UKL may be influenced by
the reshaping of the river mouth, particularly if larval suckers are more easily
transported to nearby wetlands where they may be retained longer (Markle et al.
2007 Juvenile).
Agency Lake Ranch and the Barnes properties totaling 9830 acres along the
northern and northwestern shores of Agency Lake have been acquired by
Reclamation and used as water storage areas. This action has undergone informal
section 7 consultation and Congress has approved funding for this action. The
properties will be managed in the future by USFWS as an addition to Upper
Klamath National Wildlife Refuge. Levees along these properties will be
breached in the foreseeable future (i.e., 2 to 3 years). During water storage on
these properties over the last several years wetland plant communities have reestablished
(Jason Cameron, Physical Scientist, Reclamation, pers. comm.).
Thus, when levee breaching occurs on these properties vegetation habitats should
already be relatively established. At present, it is not understood how fish will
use these future wetland habitats on the ALR and Barnes properties.
Although the impacts to fish of restoring wetland habitats along northern Upper
Klamath and Agency lakes have not yet been studied, it is reasonable to assume
that the restoration of wetlands in this area may benefit sucker populations in
UKL. The extent of the benefits remains largely unknown until results of
monitoring activities are compiled.
Chiloquin Dam Removal
The 2008 removal of Chiloquin Dam on the Sprague River will increase fish
access to habitats in the upper Sprague River watershed where sucker spawning
and rearing has been recently documented (Tyler et al. 2007, Ellsworth et al.
2007, Parrish 2007 draft). Although continued monitoring will determine the
impact of dam removal on suckers in the watershed, the perceived benefits of dam
removal are increasing fish access to the upper watershed through a redistribution
of spawning adult suckers. A redistribution of spawning adult suckers from the
lower river stretches to habitats upstream may increase sucker production in the
Williamson and Sprague rivers if spawning habitat in the lower rivers was a
limiting factor to survival of fertilized eggs. Furthermore, redistribution of
spawning suckers will reduce risks associated with catastrophic events, such as
flood scour, that can impact concentrated spawning.
The long-term benefit of dam removal may be increased sucker populations in
UKL. An increase in the numbers of spawning suckers further upriver may
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