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Western Fisheries Science News, April 2015 | Issue 3.4

Is Spawning of Endangered Suckers in the Upper Klamath Lake Affected by Low Water Levels?

Researcher with a female Lost River Sucker from Sucker Springs on Upper Klamath Lake.  Photo by USGS.

The U.S. Fish and Wildlife Service (USFWS) and the U.S. Bureau of Reclamation look to USGS for information that might help determine minimum water needs for endangered suckers. Upper Klamath Lake in southern Oregon is managed to provide irrigation water to agricultural lands in the Upper Klamath Basin as part of the federally operated

Klamath Irrigation Project, with consideration for endangered species, including Lost River and Shortnose Suckers.  Irrigation withdrawals, combined with evaporation and mandated downstream flows, deplete water supplies within the irrigation season and in the following year if subsequent winter and spring inputs are below average. The Upper Klamath Basin is entering a third year of water shortages for agriculture in 2015 with historically low snow pack in the surrounding mountains. Upper Klamath Lake was filled near capacity at the beginning of April, but snow pack in the basin is only 9% of average, the lowest since measurements began in 1958.  Due to the lack of snow, managers anticipate water shortages. If too much water is withdrawn for irriga-tion this summer, it may not be replenished in time to inundate sucker spawning habitat in the spring of 2016.  

Scientists at the WFRC Klamath Falls Field Station, in collaboration with Josh Rasmussen with the USFWS, used data from Lost River Suckers tagged with PIT tags and remotely detected at four lakeshore spawning sites to  determine whether spawning of this endangered species is affected by low water levels. The analysis will soon be published in the North American Journal of Fisheries Management. Metrics of skipped spawning, movement among spawning areas, and spawning duration among years were compared among years with contrasting spring water levels. The data set included 2010 when lake surface elevation was the lowest on record during spring sucker spawning activity.  Some aspects of sucker spawning were similar in all years, including very few individuals straying from the shoreline spawning areas to spawning locations in lake tributaries, and consistent effects of increasing water temperatures on the accumulation of fish at the spawning areas. However, the scientists found that during the extreme low water year of 2010, 14% fewer female and 8% fewer male suckers joined the shoreline spawning aggregation than in the other years. Both males and females visited fewer spawning areas within Upper Klamath Lake in 2010 than in other years, and the median duration at spawning areas in 2010 was at least 36% shorter for females and 20% shorter for males relative to other years. Given the imperiled status of the species and the declining abundance of the Lost River Sucker populations in Upper Klamath Lake (Hewitt et al. 2014), any reduction in spawning success and egg produc-tion could negatively impact recovery efforts. The results indicate that lake surface elevations above 1,262.3 to 1262.5 m would be unlikely to limit the number of spawning fish and overall egg production.

Remote PIT tag detections and physical captures of suckers at spawning areas were also used to estimate annual adult sucker survival and the number of new recruits to the adult spawning populations.  Over 6,000 tagged Lost River Suckers are detected annually at lakeshore spawning areas, over 20,000 Lost River Suckers are detected annually at river spawning areas, and about 90% of the adult Lost River Suckers survive each year.

Nevertheless, due to a lack of new spawners the Lost River Sucker spawning populations decreased by more 35% since 2001.  More than 6,000 Shortnose Suckers are detected annually in the Williamson River. Estimated annual survival for spawning Shortnose Suckers is about 80%, but due to a lack of new spawners the population has declined by more than 70% since 2001. 

These research results were used to inform the operational plan for the Klamath Irrigation Project through 2023. Upper Klamath Lake will be managed to keep lake surface elevations above 1,262.3 m above mean sea level in 90% of future years, provided that pre-season weather predictions are accurate. Water management in 2014 and average precipitation in early 2015 resulted in lake surface elevations in Upper Klamath Lake at the beginning of this spawning season of 1262.8 m above mean sea level, a level not thought to harm suckers.

Newsletter Author - Summer Burdick



The USGS WFRC Hosts Chinese Scientists:  On April 9, the WFRC fish health researchers hosted a visit from five Chinese fish health scientists from the Beijing Fisheries Research Institute and the Beijing Academy of Agriculture and Forestry Sciences.  The visitors were interested in learning about control and vaccination for the fish virus Infectious hematopoietic necrosis virus (IHNV), because this virus has been causing widespread outbreaks that are threatening the expanding rainbow trout farming industry in China.  The IHN virus is a focus of research at WFRC, as it has caused significant disease burdens in cultured trout and salmon throughout the Pacific Northwest since the 1950s. Gael Kurath and Jill Rolland presented talks on fish health aimed at the goal of transferring knowledge regarding IHNV management and control strategies developed in the United States.


Northwest Meeting Included Publishing Workshop by USGS Scientist:  Research ecologist Jeff Duda presented a workshop on best practices for submitting manuscripts for peer review at the Northwest Scientific Association meeting in Pasco, WA, on April 3rd, 2015.  Intended for both graduate students and professionals, the workshop presented information on the various important steps that authors will need to follow in preparing manuscripts for successful publication.

In the News

USGS Scientist on Oregon Public Broadcasting: On April 30, Research ecologist Jeff Duda was mentioned on Oregon Public Broadcasting’s EarthFix about an upcoming perspectives paper “1000 dams down and counting” pub-lished in Science on May 1, 2015. The article is a product from the Dam Removal Synthesis working group at the USGS John Wesley Powell Center.


USGS Scientists Receive CDI Funding to Serve Dam Removal Science Database:  The increased numbers of global dam removals, spurred on by those in the U.S., has created a need to understand the consequences of dam removal from a scientific perspective. As part of a recent USGS Powell Center working group, the USGS published the USGS Dam Removal Science Database (Bellmore et al. 2015) that contains information on the characteristics of dams that have been removed and monitored. A new project, funded by the USGS Community of Data Integration (CDI), will develop the currently static database into a dynamic, interactive element within USGS ScienceBase, where users can locate, interact with, and upload new scientific information about dam removal studies. A collaborative effort among PIs from multiple USGS centers and mission areas, the project’s goal is to interconnect existing related data and information assets within ScienceBase to dam removal projects.

USGS Scientist Coauthors Report on Suggested Fish Passage Improvements at Xayaburi Dam, Laos: On March 27, John Beeman (USGS) coauthored a report on fish passage recommendations for the Xayaburi Dam project on the Mekong River in northern Laos. On a recent trip to the Xayaburi Dam construction site, Beeman and his coauthors David Hand (U.S. Fish and Wildlife Service) and Kulthida (Ann) Techasarin (DOI - International Technical Assistance Program; DOI-ITAP) were requested by the dam design engineers to provide ideas for improvements of the planned fish passage facilities. The report is a product of the DOI-ITAP Smart Infrastructure for the Mekong Program and was sent to the U.S. State Department in Vientiane, Laos for delivery to the Laos government and Xayaburi Dam engineers.

USGS Study Examines Diel Activity Patterns of Juvenile Salmon in the Sacramento-San Joaquin River Delta: In a recent article of River Research And Applications titled “Diel activity patterns of juvenile late fall-run Chinook salmon with implications for operation of a gated water diversion in the Sacramento-San Joaquin River Delta” researchers compared diel behavior and entrainment probabilities in relation to water diversion operations. Modelling results suggest that opening the water diversion (the Delta Cross Channel) during daytime and keeping it closed during night time may allow for water diversions that minimize fish entrainment and mortality.

Plumb, J.M., N.S. Adams, R.W. Perry, C.M. Holbrook, J.G. Romine, A.R. Blake, and J.R. Burau. 2015. Diel activity patterns of juvenile late fall-run Chinook salmon with implications for operation of a gated water diversion in the Sacramento-San Joaquin River Delta. River Res. Appl. 32(4): 711-720. DOI: 10.1002/rra.2885.