My career has focused on two main areas of research 1) effects of contaminants on the aquatic environment and 2) habitat requirements of endangered species. Currently I am part of a team focused on identifying the causes of the declining Lost River and shortnose sucker populations in Upper Klamath Lake. My research is primarily composed of laboratory trials and combines my two areas of expertise.
Research Interests:
My long term research interests include examining the effects of contaminants and toxicants on imperiled species. My current research is focused on conducting laboratory experiments on Lost River suckers to try and determine what is preventing juvenile suckers from reaching maturity. It was hypothesized that age-0 juvenile sucker mortality increased due to the ingestion of prey items that had high levels of microcystin. Using laboratory experiments, I have been looking into the effects of ingested microcystin on Lost River suckers. Future laboratory experiments will focus on potential nutritional shortcomings, environmental effects on growth and condition of suckers, and effects of environmental contaminant on suckers. These laboratory experiments are fueled by observations in the field and provide supporting evidence for field and mesocosm studies.
Professional Experience
2011 to Present - Fishery Biologist, U.S. Geological Survey, Western Fisheries Research Center, Klamath Falls Field Station, Klamath Falls, OR
1999-2011 - Fishery Biologist, U.S. Geological Survey, Western Fisheries Research Center, Dixon Duty Station, Dixon, CA
1997-1999 - Biological Science Technician (Fisheries), U.S. Geological Survey, Western Fisheries Research Center, Dixon Duty Station, Dixon, CA
1995-1997 - Graduate Research Assistant, Humboldt State University Foundation, Arcata, CA
1989-1995 - Biological Science Technician (Fisheries), U.S. Fish and Wildlife Service/ National Biological Survey, National Fisheries Contaminant Research Center, Dixon Field Station, Dixon, CA
Education and Certifications
M.S. Fishery Biology. Humboldt State University, Arcata, CA
B.S. Wildlife and Fisheries Biology. University of California-Davis, Davis, CA
Affiliations and Memberships*
American Fisheries Society
Honors and Awards
Secretary Cal-Neva Chapter American Fishery Society 2011
Science and Products
Pahranagat roundtail chub (Gila robusta) - KFFS
Tribal Collaboration - KFFS
Bull Trout (Salvelinus confluentus) - KFFS
Marginal increment and age data from fin rays of endangered suckers
Data from 2018 Experiment on Effects of Temperature on Survival and Growth of Juvenile Lost River Suckers (Deltistes luxatus) naturally exposed to Ichthyobodo spp
Data for Trap Net Captured Juvenile Lost River and Shortnose Suckers from Upper Klamath Lake, Oregon
Validating a non-lethal method of aging endangered juvenile Lost River and Shortnose Suckers
Populations of imperiled Lost River Deltistes luxatus, and Shortnose Chasmistes brevirostris, suckers in Upper Klamath Lake, Oregon are experiencing long-term decreases in abundance due to limited recruitment of juvenile suckers into the adult populations. Researchers use estimated ages based on fin rays to study environmental factors affecting year-class formation, generate annual juvenile sucker
Growth, survival, and cohort formation of juvenile Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2020 monitoring report
Distribution of bull trout (Salvelinus confluentus) in conjunction with habitat and trout assemblages in creeks within the Klamath Basin, Oregon 2010–16
Water quality, instream habitat, and the distribution of suckers in the upper Lost River watershed of Oregon and California, summer 2018
Effect of temperature on survival of Lost River Suckers with a natural infection of Ichthyobodo spp.
Effects of harmful algal blooms and associated water-quality on endangered Lost River and shortnose suckers
Mortality of endangered juvenile Lost River Suckers associated with cyanobacteria blooms in mesocosms in Upper Klamath Lake, Oregon
Effects of microcystin-LR on juvenile Lost River suckers (Deltistes luxatus) during feeding trials, Upper Klamath Lake, Oregon, 2014−16
Examination of movements and survival of Pahranagat roundtail chub (Gila robusta jordani) in the Pahranagat River and adjacent waters, Nevada, 2014–18
Inter-annual variability in apparent relative production, survival, and growth of juvenile Lost River and shortnose suckers in Upper Klamath Lake, Oregon, 2001–15
Effects of Chiloquin Dam on spawning distribution and larval emigration of Lost River, shortnose, and Klamath largescale suckers in the Williamson and Sprague Rivers, Oregon
Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
Pahranagat roundtail chub (Gila robusta) - KFFS
Species Studied - Pahranagat roundtail chub (Gila robusta)Tribal Collaboration - KFFS
Factors limiting survival of juvenile endangered suckers.Bull Trout (Salvelinus confluentus) - KFFS
Species Studied - Bull Trout (Salvelinus confluentus) - Data
Marginal increment and age data from fin rays of endangered suckers
Data included in this data set are from suckers collected in Hagelstein Pond from 2014 through 2021. Data were collected on age, marginal increment, and marginal increment ratios from fin rays, and length of suckers captured during monthly sampling events. There are two levels of data. Fin ray data contains 409 records and the data file is 31 KB, repeat data contains 58 records and the data file iData from 2018 Experiment on Effects of Temperature on Survival and Growth of Juvenile Lost River Suckers (Deltistes luxatus) naturally exposed to Ichthyobodo spp
Data included in this data set are for an experiment conducted in 2018. Data were collected on survival, growth, food consumption, and Ichthyobodo copy numbers of Lost River suckers exposed to five different temperature groups. There are five levels of data. Temperature data contains 1,178 records and the data file is 35 KB, survival data contains 150 records and the data file is 3 KB, food consumData for Trap Net Captured Juvenile Lost River and Shortnose Suckers from Upper Klamath Lake, Oregon
Data included in this data set are for trap net captured juvenile suckers from Upper Klamath Lake, Oregon starting in 2001. Data were collected on fishing effort, the number of suckers captured, sucker length, and sucker species. There are two levels of data. Net level data contains 14,838 records and the data file is 2,069 KB and fish level data contains 25,236 records and the data file is 1,543 - Multimedia
- Publications
Filter Total Items: 32
Validating a non-lethal method of aging endangered juvenile Lost River and Shortnose Suckers
Populations of imperiled Lost River Deltistes luxatus, and Shortnose Chasmistes brevirostris, suckers in Upper Klamath Lake, Oregon are experiencing long-term decreases in abundance due to limited recruitment of juvenile suckers into the adult populations. Researchers use estimated ages based on fin rays to study environmental factors affecting year-class formation, generate annual juvenile sucker
Growth, survival, and cohort formation of juvenile Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2020 monitoring report
Executive SummaryPopulations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, and Clear Lake Reservoir (hereinafter, Clear Lake), California, are experiencing long-term decreases in abundance. Upper Klamath Lake populations are decreasing not only because of adult mortality, which is relatively low, but also becauDistribution of bull trout (Salvelinus confluentus) in conjunction with habitat and trout assemblages in creeks within the Klamath Basin, Oregon 2010–16
Bull trout (Salvelinus confluentus) in the Klamath Basin are on the southernmost border of the range of the species, where threats are most severe and where bull trout are most imperiled. In their recovery plan the U.S. Fish and Wildlife Service (2015, https://ecos.fws.gov/ecp/report/species-with-recovery-plans) suggested that Klamath Basin bull trout are at increased risk of extirpation due to haWater quality, instream habitat, and the distribution of suckers in the upper Lost River watershed of Oregon and California, summer 2018
Executive SummaryEndangered Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers primarily use lotic habitats during the spring spawning season in the Upper Klamath Lake watershed. However, summer-time surveys of the upper Lost River watershed in 1972, 1975 and 1989–90 indicated that adults of both endangered species use tributaries of Clear Lake Reservoir (hereafter: CleEffect of temperature on survival of Lost River Suckers with a natural infection of Ichthyobodo spp.
To compensate for low natural survival of endangered Lost River Suckers Deltistes luxatus, the U.S. Fish and Wildlife Service and the Klamath Tribes have initiated captive rearing programs. We conducted laboratory experiments intended to determine the temperature for optimum growth of juvenile Lost River Suckers; however, due to an unanticipated infection with Ichthyobodo spp., we instead estimateEffects of harmful algal blooms and associated water-quality on endangered Lost River and shortnose suckers
Anthropogenic eutrophication contributes to harmful blooms of cyanobacteria in freshwater ecosystems worldwide. In Upper Klamath Lake, Oregon, massive blooms of Aphanizomenon flos-aquae and smaller blooms of other cyanobacteria are associated with cyanotoxins, hypoxia, high pH, high concentrations of ammonia, and potentially hypercapnia. Recovery of the endangered Lost River sucker Deltistes luxatMortality of endangered juvenile Lost River Suckers associated with cyanobacteria blooms in mesocosms in Upper Klamath Lake, Oregon
Unsustainably high mortality within the first 2 years of life prevents endangered Lost River Suckers Deltistes luxatus in Upper Klamath Lake, Oregon, from recruiting to spawning populations. Massive blooms of the cyanobacterium Aphanizomenon flos‐aquae and their subsequent death and decay in the lake (bloom‐crashes) are associated with high pH, low percent oxygen saturation, high total ammonia conEffects of microcystin-LR on juvenile Lost River suckers (Deltistes luxatus) during feeding trials, Upper Klamath Lake, Oregon, 2014−16
Executive SummaryHistorically, populations of Lost River suckers (Deltistes luxatus) of the Upper Klamath Basin were so numerous that they were commercially harvested; however, declining numbers throughout the 20th century led to the listing of the species under the United States Endangered Species Act in 1988. Habitat destruction, poor water quality, competition with (and predation by) nonnativeExamination of movements and survival of Pahranagat roundtail chub (Gila robusta jordani) in the Pahranagat River and adjacent waters, Nevada, 2014–18
Executive SummaryThe Pahranagat roundtail chub (Gila robusta jordani; hereinafter “chub”) was federally listed as endangered in 1970 (U.S. Fish and Wildlife Service, 1970). In the decades following the listing, the chub has declined to extremely low numbers (Tuttle and others, 1990; Guadalupe, 2014). Loss of available habitat appears to be one of the main reasons for the decline of this species. HInter-annual variability in apparent relative production, survival, and growth of juvenile Lost River and shortnose suckers in Upper Klamath Lake, Oregon, 2001–15
Executive SummaryPopulations of the once abundant Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) of the Upper Klamath Basin, decreased so substantially throughout the 20th century that they were listed under the Endangered Species Act in 1988. Major landscape alterations, deterioration of water quality, and competition with and predation by exotic species are listedEffects of Chiloquin Dam on spawning distribution and larval emigration of Lost River, shortnose, and Klamath largescale suckers in the Williamson and Sprague Rivers, Oregon
Chiloquin Dam was constructed in 1914 on the Sprague River near the town of Chiloquin, Oregon. The dam was identified as a barrier that potentially inhibited or prevented the upstream spawning migrations and other movements of endangered Lost River (Deltistes luxatusSelenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California
Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-yearNon-USGS Publications**
Martin, B.A. 1997. Effects of ambient water quality on the endangered Lost River sucker (Deltistes luxatus) in Upper Klamath Lake, Oregon. M.S. thesis, Humboldt State University, Arcata, CA. 55 pp.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government