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
Stress tolerance in plants via habitat-adapted symbiosis
We demonstrate that native grass species from coastal and geothermal habitats require symbiotic fungal endophytes for salt and heat tolerance, respectively. Symbiotically conferred stress tolerance is a habitat-specific phenomenon with geothermal endophytes conferring heat but not salt tolerance, and coastal endophytes conferring salt but not heat tolerance. The same fungal species isolated from p
Molecular detection of native and invasive marine invertebrate larvae present in ballast and open water environmental samples collected in Puget Sound
Non-native marine species have been and continue to be introduced into Puget Sound via several vectors including ship's ballast water. Some non-native species become invasive and negatively impact native species or near shore habitats. We present a new methodology for the development and testing of taxon specific PCR primers designed to assess environmental samples of ocean water for the presence
Development of a molecular diagnostic system to discriminate Dreissena polymorpha (zebra mussel) and Dreissena bugensis (quagga mussel)
A 3-primer PCR system was developed to discriminate invasive zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel. The system is based on: 1) universal primers that amplifies a region of the nuclear 28s rDNA gene from both species and 2) a species-specific primer complementary to either zebra or quagga mussel. The species-specific primers bind to sequences between the binding sites
Salinity adaptation of the invasive New Zealand mud snail (<i>Potamopyrgus antipodarum</i>) in the Columbia River estuary (Pacific Northwest, USA): Physiological and molecular studies
In this study, we examine salinity stress tolerances of two populations of the invasive species New Zealand mud snail Potamopyrgus antipodarum, one population from a high salinity environment in the Columbia River estuary and the other from a fresh water lake. In 1996, New Zealand mud snails were discovered in the tidal reaches of the Columbia River estuary that is routinely exposed to salinity at
Intragenomic sequence variation at the ITS1 - ITS2 region and at the 18S and 28S nuclear ribosomal DNA genes of the New Zealand mud snail, <i>Potamopyrgus antipodarum</i> (Hydrobiidae: mollusca)
Molecular genetic analysis was conducted on two populations of the invasive non-native New Zealand mud snail (Potamopyrgus antipodarum), one from a freshwater ecosystem in Devil's Lake (Oregon, USA) and the other from an ecosystem of higher salinity in the Columbia River estuary (Hammond Harbor, Oregon, USA). To elucidate potential genetic differences between the two populations, three segments of
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
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 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
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
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
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
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
Stress tolerance in plants via habitat-adapted symbiosis
We demonstrate that native grass species from coastal and geothermal habitats require symbiotic fungal endophytes for salt and heat tolerance, respectively. Symbiotically conferred stress tolerance is a habitat-specific phenomenon with geothermal endophytes conferring heat but not salt tolerance, and coastal endophytes conferring salt but not heat tolerance. The same fungal species isolated from pMolecular detection of native and invasive marine invertebrate larvae present in ballast and open water environmental samples collected in Puget Sound
Non-native marine species have been and continue to be introduced into Puget Sound via several vectors including ship's ballast water. Some non-native species become invasive and negatively impact native species or near shore habitats. We present a new methodology for the development and testing of taxon specific PCR primers designed to assess environmental samples of ocean water for the presenceDevelopment of a molecular diagnostic system to discriminate Dreissena polymorpha (zebra mussel) and Dreissena bugensis (quagga mussel)
A 3-primer PCR system was developed to discriminate invasive zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussel. The system is based on: 1) universal primers that amplifies a region of the nuclear 28s rDNA gene from both species and 2) a species-specific primer complementary to either zebra or quagga mussel. The species-specific primers bind to sequences between the binding sitesSalinity adaptation of the invasive New Zealand mud snail (<i>Potamopyrgus antipodarum</i>) in the Columbia River estuary (Pacific Northwest, USA): Physiological and molecular studies
In this study, we examine salinity stress tolerances of two populations of the invasive species New Zealand mud snail Potamopyrgus antipodarum, one population from a high salinity environment in the Columbia River estuary and the other from a fresh water lake. In 1996, New Zealand mud snails were discovered in the tidal reaches of the Columbia River estuary that is routinely exposed to salinity atIntragenomic sequence variation at the ITS1 - ITS2 region and at the 18S and 28S nuclear ribosomal DNA genes of the New Zealand mud snail, <i>Potamopyrgus antipodarum</i> (Hydrobiidae: mollusca)
Molecular genetic analysis was conducted on two populations of the invasive non-native New Zealand mud snail (Potamopyrgus antipodarum), one from a freshwater ecosystem in Devil's Lake (Oregon, USA) and the other from an ecosystem of higher salinity in the Columbia River estuary (Hammond Harbor, Oregon, USA). To elucidate potential genetic differences between the two populations, three segments ofHealth 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 onJuvenile 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 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 waterConcentrations 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 quantitativJuvenile 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 aggreEvaluation 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