Western Fisheries Science News, August 2014 | Issue 2.8

Release Date:

Research Underway to Investigate Mortality of Endangered Lost River and Shortnose Suckers in the Upper Klamath Basin

Upper Klamath Lake

Upper Klamath Lake. Photo by Brian Hayes, USGS.

Recovery of the Lost River sucker and shortnose sucker—fishes endemic to the Upper Klamath Basin of Oregon and California and federally listed as endangered under the Endangered Species Act—could have a limited timeline.  Recruitment of new spawners has been low since the early 1990’s and recent sampling indicates that the juvenile life stages suffer high mortality in Upper Klamath Lake, Oregon, during summer and fall.  The cause of prolonged lack of recruitment of new individuals into endangered Lost River sucker and shortnose sucker spawning populations in Upper Klamath Lake is unclear.  Poor water quality may be contributing to high mortality with factors that include various infectious agents, high ammonia, and low dissolved oxygen.  The coincidence of apparent juvenile sucker mortality with periods of hypoxia, decay of massive cyanobacteria blooms, and episodic high concentrations of cyanotoxins (microsystin), points to factors associated with poor water quality. Limited recruitment is the primary short-term threat to the persistence of these species, but without knowing the cause effective recovery actions cannot be executed.  Clear Lake Reservoir, located in Modoc County, California, and considered as the other main water body for recovery planning of these fishes, offers some hope for understanding the limited recruitment.  While juvenile suckers in the Upper Klamath Lake are experiencing almost complete mortality in the first year, some recruitment is occurring in Clear Lake (primarily for the shortnose sucker).  Difference in the two systems in regards to hydrology, water quality, and algal bloom dynamics offer an opportunity to identify factors for recruitment success. 

Lost River suckers

Lost River Suckers spawning at the shoreline springs in Upper Klamath Lake.  Photo by USGS.

Researchers from the USGS-WFRC Klamath Falls Field Station are working with the U.S. Fish and Wildlife Service and USGS partners from WFRC Fish Health Section, the Columbia Environmental Research Center, and the Oregon Water Science Center on a new study to compare early life history dynamics and the factors affecting survival of young suckers in Upper Klamath and Clear Lakes.  They are documenting specific water quality and fish differences between Upper Klamath and Clear Lakes and will leverage comparative information to shed light on factors that are limiting the populations in the two lakes.  Throughout the summer and fall, researchers will be sampling fish, tagging juvenile suckers, assessing bird predation levels, and collecting water quality samples.  Through this line of research they hope to reveal potential explanations for the apparent juvenile sucker mortality in Upper Klamath Lake and help support future recovery efforts.

The Klamath Falls Field Station, located in Klamath Falls, Oregon, is one of four field stations of Western Fisheries Research Center.  It was established in 1999 to conduct research within the Klamath River Basin.  Scientists conduct research into the life history, population dynamics, and behavioral ecology of fishes in lentic and lotic habitats within the Basin. Research at the Klamath Falls Field Station has been helping managers make informed decisions about resource use in this complex environment. 

Newsletter Author - Rachel Reagan



USGS Intern Conducts Research at University of Kent:  On September 7-21, Pathways Career Intern Rachel Reagan will travel to the University of Kent, Canterbury, UK, as a visiting researcher. Reagan will work with Jesse O’Hanley (collaborator and committee member) to further develop analytical models for fish passage optimization.  O’Hanley will provide expertise to extend optimization models for fish passage as they incorporate changes in hydrology, risk, and climate change impacts into the models.  The project will provide decision support tools for natural resource managers.  Reagan is a Pathways Career Intern with WFRC and advised by USGS Ecologist Jason Dunham.


USGS Presents at International Symposium on Aquatic Animal Health:  On August 31 - September 4, scientists from the WFRC will participate in the 7th International Symposium on Aquatic Animal Health (ISAAH) in Portland, OR.  The ISAAH is a gathering of international fish health professionals, occurring every four years. USGS scientists are authors or coauthors on nine different oral presentations. The presentations cover a range of research focused on important viral, bacterial and parasitic fish pathogens, as well as studies addressing the impact of environmental endocrine disrupters on the fish immune system. Additionally, USGS scientists Paul Hershberger, Gael Kurath and WFRC Director Jill Rolland are playing key roles in organizing the symposium.

Western Fisheries Research Center participates in Northwest Climate Science Center’s Climate Boot Camp:  On August 10-16, WFRC scientist Jill Hardiman participated in the Northwest Climate Science Center’s Climate Boot Camp.  The intensive week-long course was held at Silver Falls State Park, OR, where students, managers, tribal and first nations, and  research scientists convened to discuss climate change in the Pacific Northwest.  Participants were given an overview of climate change processes, with focus areas on resource management issues around sea level rise and loss of tidal wetlands, impacts to salmonids, lamprey, and amphibians, traditional foods and gathering places, and how to communicate science to a diverse audience. 

USGS Hosts Summer Program Students:  On July 23rd, the WFRC hosted high school students from the New Start High School from Burien, WA.  The students toured the WFRC facility and asked questions about working for USGS and careers in science. The New Start High School is an alternative school for kids at risk to not graduate and the summer program is a work study program.

USGS Western Fisheries Research Center Participates in Feds Feed Families Campaign:  The WFRC—Columbia River Research Laboratory participated in the 2014 Feds Feed Families Campaign by donating 114 pounds of non-perishable food and 46 pounds of perishable food.  Donations were made to the Skamania County Food Bank in Stevenson, WA, and the FISH food bank in Hood River, OR.  Food banks across the country are facing severe shortages of non-perishable items. Through this program we have been providing much-needed food support to neighbors, families, and communities across the Nation.

In the News

On July 30th, WFRC scientist Pat Connolly was quoted in Nature International weekly journal of science.  The article titled “Dam removals: Rivers of the run” describes the trend of dam removals and the restoration of habitat for fish species.


Beeman, J.W., H.C. Hansel, A.C. Hansen, S.D. Evans, P.V. Haner, T.W. Hatton, E.E. Kofoot, J.M. Sprando, and C.D. Smith. 2014.  Behavior and dam passage of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March 2012-February 2013: U.S. Geological Survey Open-File Report 2014-1177, 52 p. DOI:  10.3133/ofr20141177.

Bellmore, J.R., C.V. Baxter, and P. Connolly. 2014. Spatial complexity reduces interaction strengths in the meta-food web of a river floodplain mosaic. Ecol. 96(1): 274-283. DOI: 10.1890/14-0733.1.

Hatten, J.R. 2014.  Mapping and monitoring Mount Graham red squirrel habitat with Lidar and Landsat imagery. Ecol. Model. 289: 106-123. DOI: 10.1016/j.ecolmodel.2014.07.004.