Skip to main content
U.S. flag

An official website of the United States government

Western Fisheries Science News, August 2016 | Issue 4.8

September 5, 2016

Mesocosms Give Us the Fish-eye View into the Lives and Deaths of Endangered Suckers

A mesocosm deployed in Upper Klamath Lake, complete with antenna arrays that are powered by solar panels. Photo by USGS.

New insights into the secret lives of juvenile Lost River suckers are being made possible through the use of mesocosms, underwater experimental net pens.

Lost River and shortnose suckers— long-lived members of the family Catostomidae and endemic to the Klamath River Basin— are listed as endangered under the Endangered Species Act and are a high priority for recovery. Recent research by the Western Fisheries Research Center (WFRC), Klamath Falls Field Station (KFFS) indicates that despite relatively high adult survival in most years, both species have experienced substantial decreases in abundance in Upper Klamath Lake because losses from mortality have not been balanced by recruitment of new individuals to spawning populations. The vast majority of Lost River and shortnose suckers presently making up spawning populations were hatched in the early 1990s.  As the majority of shortnose suckers reach the maximum age reported for the species of about 30 years, their populations are expected to critically decline. Populations of Lost River suckers, that can live to be 50 years old, may have more time.  Research indicates that recruitment of new spawners is limited by high first year mortality, rather than emigration from the lake or some other factor. Identifying the specific factors that contribute to or cause juvenile sucker mortality is critical for effective management and eventually the recovery of both sucker species.

Concerned about fish health and condition, KFFS researchers Summer Burdick and Danielle Hereford teamed up with WFRC fish health specialists Diane Elliott, Carla Conway, and Maureen Purcell to investigate the health and condition of juvenile suckers relative to water quality and fish communities in Upper Klamath. They also collaborated with microbiologist Sara Eldridge and hydrologist Liam Schenk from the USGS Oregon Water Science Center to come up with the use of experimental mesocosms that would allow them to examine the natural environment under controlled conditions, providing a link between field surveys and controlled laboratory experiments.           

Underwater image of fish in a mesocosm. Photo by USGS.

The mesocosms were designed and built by Todd Perry and his team at KFFS. They have been deployed in three areas of Upper Klamath Lake, complete with a large net pen, PVC frame, floating dock, Passive Integrated Transponder (PIT) tag antennas, bird-control netting and water quality monitors. Weekly microcystin and ammonia measurements are compared to juvenile sucker mortality rates to determine if there is a relationship. Hatchery reared juvenile Lost River suckers were PIT-tagged, placed in the mesocosms in July of this year, and their vertical movements are being continually monitored using PIT tag technology. The mesocosms are checked three times per week for mortalities and moribund (fish close to death), which are taken, preserved and sent for histological analyses.

The mesocosms have made it possible to track daily move-ment patterns, identify precise (within several hours) timing of mortality, and to capture some suckers near death. Teaming up with WFRC’s headquarters has allowed scientists to learn more about the environmental stresses and potential causes of mortality for suckers in the mesocosms. Having this type of insight is valuable when considering fish in the wild that are harder to observe. As the project wraps up, researchers are beginning to evaluate the data. One preliminary observation is that there appears to be a difference in survival among sites, which may lead to clues about causes of mortality (more information will be available next spring).

This tool is also allowing the researchers to start thinking about some new questions associated with fish behavior. Researchers have deployed Go-Pro cameras to capture some unique footage of suckers within the mesocosm, which is allowing researchers to see, as a fish, the changes in behavior and condition. Gaining this type of insight will be instrumental in guiding fish recovery efforts.

Newsletter Author - Rachel Reagan



USGS Scientist Presents Tidal Wetland Research at Future of Our Salmon Technical Workshop: Fish biologist Collin Smith presented his research on using acoustic camera technologies to monitor fish behavior and movements in response to changing hydrodynamic conditions at the entrance to a tidally influenced wetland, at the workshop in Spokane, WA. The event focused on technical aspects of floodplain management within the Columbia River Basin, and was convened by the Columbia-River Inter-Tribal Fish Commission. 

USGS Hosts Visit by Congressman Kilmer: On August 12, 2016, the WFRC Marrowstone Marine Field Station hosted a visit from Congressman Derek Kilmer (Washington’s 6th District). Kilmer was particularly interested in learning about some of the disease issues that impact herring in the Puget Sound.

White House Recognition of Prize Competition Efforts: Prize competition efforts were given recognition in a White House blog release. One agency in particular, the U.S. Bureau of Reclamation (BOR), established the Water Prize Competition Center, an interagency center that is working with other Federal agencies to collaboratively design, launch, and judge prize competitions for innovative solutions related to the several mission-critical areas including infrastructure sustainability, ecosystem restoration, and water availability was mentioned. Scientists from the WFRC have been working directly with the BOR on many aspects of these competitions.

In the News

Research scientist Theresa “Marty” Liedtke from the WFRC was featured in an article of the Encyclopedia of Puget Sound. The article titled “The secret lives of forage fish: Where do they go when we aren’t looking?” describes research being done on important forage fish to help understand how many there are, where they go, and how we can preserve their populations for the future.

On August 2, 2016, WFRC scientist Jim Hatten was featured on National Public Radio KJZZ (Phoenix, AZ), discussing recent research about how climate change may affect birds and reptiles in the Southwest. 

On July 16, 2016, research by WFRC scientist Jim Hatten and co-authors was featured in the Summit County Citizens Voice about how climate change may affect birds and reptiles in the Southwest.


New Report on Behavior and Movement of Hatchery and Wild Adult Salmon and Steelhead: USGS researchers have evaluated various aspects of a salmon and steelhead reintroduction program in the Cowlitz River Basin since 1997. A new report was recently completed which summarizes findings from telemetry studies that were conducted to describe behavior and movement patterns of hatchery-produced and naturally-produced steelhead, Chinook salmon and coho salmon following outplanting in areas located upstream of dams. The study also evaluated differences between release sites to determine if releasing fish directly into rivers near spawning habitat resulted in higher numbers of fish present on the spawning grounds.

Kock, T.J., B.K. Ekstrom, T.L. Liedtke, J.D. Serl, and Mike Kohn. 2016. Behavior patterns and fates of adult steelhead, Chinook salmon, and coho salmon released into the upper Cowlitz River Basin, Washington, 2005-09 and 2012: U.S. Geological Survey Open-File Report 2016-1144, 36 p. 

New Publication Investigates Temperature-Influenced Binge Feeding of Piscivorous Fish: Understanding the limits of consumption is important for determining trophic influences on ecosystems and predator adaptations to inconsistent prey availability. Fishes have been observed to consume beyond what is sustainable (i.e. digested on a daily basis) when given the opportunity, but this phenomenon of binge-feeding has been largely overlooked. In a new publication in Journal of Animal Ecology, scientists from University of British Columbia and USGS demonstrate that high rates of binge-feeding by bull trout occur regularly in both laboratory and field settings, and that temperature influences the extent of feeding. This has important implications for both predators and prey. A predator's ability to binge-feed and continue to feed can increase prey mortality, especially during short episodic events such smolt outmigration.For species like bull trout and other charr that routinely experience long periods of scarce food availability, binge-feeding can contribute significantly to their annual energy budget in support of reproduction and growth. Results shed light on the potential for binge-feeding playing an important role in the ecology of both predators and prey.

Furey, N.B., S.G. Hinch, M.G. Mesa, and D.A. Beauchamp. 2016. Piscivorous fish exhibit temperature-influenced binge feeding during an annual prey pulse. Journal of Animal Ecology 85(5): 1307-1317.

New USGS Report Introduces Dam Removal Information Portal: The removal of dams has recently increased over historical levels due to aging infrastructure, changing societal needs, and modern safety standards rendering some dams obsolete. Where possibilities for river restoration, or improved safety, exceed the benefits of retaining a dam, removal is more often being considered as a viable option. Yet, as this is a relatively new development in the history of river management, science is just beginning to guide our understanding of the physical and ecological implications of dam removal. In a recent USGS Open-file report, scientists created a database visualization tool, the Dam Removal Information Portal (DRIP), to display map-based, interactive information about the scientific studies associated with dam removals. This tool will serve both as a bibliographic source as well as a link to other existing databases that synthesize the existing scientific studies associated with dam removals.

Duda, J.J., Wieferich, D.J., Bristol, R.S., Bellmore, J.R., Hutchison, V.B., Vittum, K.M., Craig, Laura, and Warrick, J.A., 2016, Dam Removal Information Portal (DRIP) — A map-based resource linking scientific studies and associated geospatial information about dam removals: U.S. Geological Survey Open-File Report 2016-1132, 14 p.

New Publication Investigates Diversity, Transmission Patterns, and Phylogeography of Parasite in Marine Fishes: Ichthyophonus hoferi is arguably the most ecologically and economically significant parasite of wild marine fishes, with resulting disease epizootics repeatedly causing population-level impacts throughout the past century. In a recent paper, USGS scientists describe six unique genetic types of the parasite, with the most widespread type commonly occurring among marine fishes throughout the northern hemisphere. These results indicate that Ichthyophonus parasites represent a species complex, with clear genetic distinction occurring between the ubiquitous marine species and the type species I. hoferi.

Gregg, J.L., R.L. Powers, M.K. Purcell, C.S. Friedman, and P.K. Hershberger. 2016. Ichthyophonus parasite phylogeny based on ITS rDNA structure prediction and alignment identifies six clades, with a single dominant marine type. Dis. Aquat. Org. 120(2): 125-141.

USGS Scientist Publishes Chapters in New Book "Aquaculture Virology": USGS scientist Bill Batts recently published two chapters in a new book titled "Aquaculture Virology", published through Elsevier Inc. and edited by Dr. Kibenge and Dr. Godoy. One chapter titled "Hepeviruses of Fish" includes the cutthroat trout virus (CTV) which so far has been detected in seven different species of trout from ten western states and now has been found in fish as far away as Wisconsin and Pennsylvania and further north to Alberta, and New Brunswick, Canada. This virus does not cause mortalities in any fish studied thus far, but is of concern due to widespread dissemination. The second chapter, titled "Paramyxoviruses of Fish", was co-authored by Bill Batts in collaboration with Dr. Ted Meyers of the Alaska Department of Fish and Game. They describe Pacific and Atlantic salmon paramyxoviruses detected in spawning Chinook salmon along the West Coast of North America and from Atlantic salmon in Norway. Although the Pacific salmon virus isolations have been from asymptomatic adults, the Atlantic salmon virus was associated with respiratory gill disease, similar to the respiratory nature of several human paramyxoviruses such as parainfluenzavirus and respiratory syncytial virus (RSV). Cell culture and molecular detection methods are discussed for optimum identification of these fish viruses.

Batts, W.N. 2016. Hepeviruses of fish, Chapter 24 in Kibenge, F.S.B. and M.G. Godoy, eds., Aquaculture Virology. Elsevier Inc., p. 365-369. ISBN: B978-0-12-801573-5. DOI: 10.1016/B978-0-12-801573-5.00001-2.