Marshal is a Biological Science Laboratory Technician at the Western Fisheries Research Center.
Research Interests:
I am a member of the Ecology Section at the U.S. Geological Survey's Western Fisheries Research Center in Seattle, WA. I have participated in several projects using environmental DNA (eDNA) technology, which includes involvement in the entire process from molecular assay design, field sampling and laboratory processing/analysis. We have used eDNA based methods to:
- Monitor recolonization, distribution and migration of fish species
- Provide abundance/biomass/density estimates
- Quantification of biodiversity in Marine communities.
I am also involved in many other exciting projects such as the genetic analysis of several fish species (including the development of genetic species marker for the endangered Lost River and shortnose suckers in the Klamath Basin), using food web interactions and bioenergetics to study juvenile salmon survival in Puget Sound, and USGS Elwha River nearshore long-term dam removal monitoring project.
Professional Experience
4/2009 to Present- Biological Science Laboratory Technician, U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA
2002 - 4/2009- Research Scientist, University of Washington, Seattle, WA
Education and Certifications
B.S. Botany, University of Washington, Seattle, WA
Honors and Awards
1/2010 - Star Award, U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA
Science and Products
Environmental DNA (eDNA) is an Effective Tool to Track Recolonizing Migratory Fish Following Large-Scale Dam Removal, field data
We collected environmental DNA (eDNA) data from the Elwha River, home to the world?s largest dam removal project, to track the spatial and temporal patterns of species responses following dam removal. In total, we collected data for 11 different fish taxa, sampled at 25 sites ranging across 56 river kilometers in a wilderness river for 4 years following dam removal. We show that eDNA can effective
Concentrations of environmental DNA (eDNA) during sockeye salmon spawning in 2016, Hansen Creek, Alaska, USA
This dataset contains environmental DNA (eDNA) concentrations and spawning adult abundances for sockeye salmon (Oncorhynchus nerka) in Hansen Creek, a small tributary in the Wood River watershed, southeast Alaska, USA. We took temporally- and spatially-replicated eDNA samples during the spawning period (mid-July through August), along with fish counts (live, naturally dead, and killed), dissolved
Filter Total Items: 17
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—2019 Monitoring Report
Populations 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 due to adult mortality, which is relatively low, but also because they are not being
Environmental DNA is an effective tool to track recolonizing migratory fish following large‐scale dam removal
Environmental DNA (eDNA) has emerged as a potentially powerful tool for use in conservation and resource management, including for tracking the recolonization dynamics of fish populations. We used eDNA to assess the effectiveness of dam removal to restore fish passage on the Elwha River in Washington State (USA). Using a suite of 11 species‐specific eDNA polymerase chain reaction (PCR) assays, we
Juvenile Lost River and shortnose sucker year-class formation, survival, and growth in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2018 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 becaus
Juvenile Lost River and shortnose sucker year-class formation, survival, and growth in Upper Klamath Lake, Oregon and Clear Lake Reservoir, California—2017 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 referred to as Clear Lake; fig. 1), California, are experiencing long-term declines in abundance. Upper Klamath Lake populations are decreasing because juvenile suckers are not surviving and recruiti
Development of two quantitative PCR assays for detection of several Cottus species from environmental DNA in Pacific coast watersheds of North America
We developed two quantitative PCR assays for use with environmental DNA (eDNA) to detect numerous species in the genus Cottus that are indigenous to the Pacific coast watersheds of North America. We conducted in vitro assay validations on ten Cottus species and 32 potentially co-occurring non-Cottus species. We demonstrate the efficacy of these assays by field testing eDNA samples collected from s
Evaluation of environmental DNA surveys for identifying occupancy and spatial distribution of Pacific Lamprey (Entosphenus tridentatus) and Lampetra spp. in a Washington coast watershed
Surveys of environmental DNA (eDNA) have become an important and multifaceted tool for monitoring and identifying distributions and occupancy of aquatic species. This tool is attractive because it is powerful, easy to apply, and provides an alternative to traditional field survey methods. However, validating eDNA survey methods against traditional field survey methods is warranted prior to their a
Juvenile Lost River and shortnose sucker year class strength, survival, and growth in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2016 Monitoring Report
Executive SummaryThe largest populations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) exist in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California. Upper Klamath Lake populations are decreasing because adult mortality, which is relatively low, is not being balanced by recruitment of young adult suckers into known spawning aggre
Concentrations of environmental DNA (eDNA) reflect spawning salmon abundance at fine spatial and temporal scales
Developing fast, cost-effective assessments of wild animal abundance is an important goal for many researchers, and environmental DNA (eDNA) holds much promise for this purpose. However, the quantitative relationship between species abundance and the amount of DNA present in the environment is likely to vary substantially among taxa and with ecological context. Here, we report a strong quantitativ
Health and condition of endangered young-of-the-year Lost River and Shortnose suckers relative to water quality in Upper Klamath Lake, Oregon, 2014–2015
Most mortality of endangered Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers in Upper Klamath Lake, Oregon, occurs within the first year of life. Juvenile suckers in Clear Lake Reservoir, California, survive longer and may even recruit to the spawning populations. In a previous (2013–2014) study, the health and condition of juvenile suckers and the dynamics of water
Juvenile sucker cohort tracking data summary and assessment of monitoring program, 2015
Populations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, are experiencing long-term declines in abundance. Upper Klamath Lake populations are decreasing because adult mortality, which is relatively low, is not being balanced by recruitment of young adult suckers into known adult spawning aggregations. Previous
Health and condition of endangered juvenile Lost River and shortnose suckers relative to water quality and fish assemblages in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California
Executive Summary
Most mortality of endangered Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers in Upper Klamath Lake, Oregon, appears to occur within the first year of life. However, juvenile suckers in Clear Lake Reservoir, California, appear to survive longer and may even recruit to the spawning populations. Our goal in this study was to develop productive lines of
Development of 20 TaqMan assays differentiating the endangered shortnose and Lost River suckers
Accurate species identification is vital to conservation and management of species at risk. Species identification is challenging when taxa express similar phenotypic characters and form hybrids, for example the endangered shortnose sucker (Chasmistes brevirostris) and Lost River sucker (Deltistes luxatus). Here, we developed 20 Taqman assays that differentiate these species (19 nuclear DNA and on
Science and Products
- Data
Environmental DNA (eDNA) is an Effective Tool to Track Recolonizing Migratory Fish Following Large-Scale Dam Removal, field data
We collected environmental DNA (eDNA) data from the Elwha River, home to the world?s largest dam removal project, to track the spatial and temporal patterns of species responses following dam removal. In total, we collected data for 11 different fish taxa, sampled at 25 sites ranging across 56 river kilometers in a wilderness river for 4 years following dam removal. We show that eDNA can effectiveConcentrations of environmental DNA (eDNA) during sockeye salmon spawning in 2016, Hansen Creek, Alaska, USA
This dataset contains environmental DNA (eDNA) concentrations and spawning adult abundances for sockeye salmon (Oncorhynchus nerka) in Hansen Creek, a small tributary in the Wood River watershed, southeast Alaska, USA. We took temporally- and spatially-replicated eDNA samples during the spawning period (mid-July through August), along with fish counts (live, naturally dead, and killed), dissolved - Publications
Filter Total Items: 17
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—2019 Monitoring Report
Populations 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 due to adult mortality, which is relatively low, but also because they are not beingEnvironmental DNA is an effective tool to track recolonizing migratory fish following large‐scale dam removal
Environmental DNA (eDNA) has emerged as a potentially powerful tool for use in conservation and resource management, including for tracking the recolonization dynamics of fish populations. We used eDNA to assess the effectiveness of dam removal to restore fish passage on the Elwha River in Washington State (USA). Using a suite of 11 species‐specific eDNA polymerase chain reaction (PCR) assays, weJuvenile Lost River and shortnose sucker year-class formation, survival, and growth in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2018 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 becausJuvenile Lost River and shortnose sucker year-class formation, survival, and growth in Upper Klamath Lake, Oregon and Clear Lake Reservoir, California—2017 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 referred to as Clear Lake; fig. 1), California, are experiencing long-term declines in abundance. Upper Klamath Lake populations are decreasing because juvenile suckers are not surviving and recruitiDevelopment of two quantitative PCR assays for detection of several Cottus species from environmental DNA in Pacific coast watersheds of North America
We developed two quantitative PCR assays for use with environmental DNA (eDNA) to detect numerous species in the genus Cottus that are indigenous to the Pacific coast watersheds of North America. We conducted in vitro assay validations on ten Cottus species and 32 potentially co-occurring non-Cottus species. We demonstrate the efficacy of these assays by field testing eDNA samples collected from sEvaluation of environmental DNA surveys for identifying occupancy and spatial distribution of Pacific Lamprey (Entosphenus tridentatus) and Lampetra spp. in a Washington coast watershed
Surveys of environmental DNA (eDNA) have become an important and multifaceted tool for monitoring and identifying distributions and occupancy of aquatic species. This tool is attractive because it is powerful, easy to apply, and provides an alternative to traditional field survey methods. However, validating eDNA survey methods against traditional field survey methods is warranted prior to their aJuvenile Lost River and shortnose sucker year class strength, survival, and growth in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California—2016 Monitoring Report
Executive SummaryThe largest populations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) exist in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California. Upper Klamath Lake populations are decreasing because adult mortality, which is relatively low, is not being balanced by recruitment of young adult suckers into known spawning aggreConcentrations of environmental DNA (eDNA) reflect spawning salmon abundance at fine spatial and temporal scales
Developing fast, cost-effective assessments of wild animal abundance is an important goal for many researchers, and environmental DNA (eDNA) holds much promise for this purpose. However, the quantitative relationship between species abundance and the amount of DNA present in the environment is likely to vary substantially among taxa and with ecological context. Here, we report a strong quantitativHealth and condition of endangered young-of-the-year Lost River and Shortnose suckers relative to water quality in Upper Klamath Lake, Oregon, 2014–2015
Most mortality of endangered Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers in Upper Klamath Lake, Oregon, occurs within the first year of life. Juvenile suckers in Clear Lake Reservoir, California, survive longer and may even recruit to the spawning populations. In a previous (2013–2014) study, the health and condition of juvenile suckers and the dynamics of waterJuvenile sucker cohort tracking data summary and assessment of monitoring program, 2015
Populations of federally endangered Lost River (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) in Upper Klamath Lake, Oregon, are experiencing long-term declines in abundance. Upper Klamath Lake populations are decreasing because adult mortality, which is relatively low, is not being balanced by recruitment of young adult suckers into known adult spawning aggregations. PreviousHealth and condition of endangered juvenile Lost River and shortnose suckers relative to water quality and fish assemblages in Upper Klamath Lake, Oregon, and Clear Lake Reservoir, California
Executive Summary Most mortality of endangered Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers in Upper Klamath Lake, Oregon, appears to occur within the first year of life. However, juvenile suckers in Clear Lake Reservoir, California, appear to survive longer and may even recruit to the spawning populations. Our goal in this study was to develop productive lines ofDevelopment of 20 TaqMan assays differentiating the endangered shortnose and Lost River suckers
Accurate species identification is vital to conservation and management of species at risk. Species identification is challenging when taxa express similar phenotypic characters and form hybrids, for example the endangered shortnose sucker (Chasmistes brevirostris) and Lost River sucker (Deltistes luxatus). Here, we developed 20 Taqman assays that differentiate these species (19 nuclear DNA and on - Multimedia