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Elena Nilsen

Elena Nilsen is a research chemist in the USGS Oregon Water Science Center

Elena Nilsen is a Research Chemist and Team Lead at the U.S. Geological Survey Oregon Water Science Center in Portland, OR. She studies contaminants of emerging concern (CECs) and other threats to aquatic foodwebs in rivers, estuaries, and coastal ocean habitats. Elena has worked extensively on methods development and refinement in collaboration with the USGS National Water Quality Laboratory. She completed a Bachelor of Science degree in biology at UC San Diego and a Doctorate in marine geochemistry at UC Santa Cruz.  She started with the USGS as a Mendenhall Post-doctoral Fellow with the USGS Pacific Coastal and Marine Science Center in the San Francisco Bay Area studying impacts of contamination on estuarine ecology and geochemistry.  She has been with the Oregon Water Science Center since 2007.

Research Interests

Contaminants of emerging concern (CECs); sediment and tissue chemistry; endocrine disruption; contaminant impacts on First Food species, e.g., Pacific lamprey, white sturgeon, salmonids, shellfish; primary productivity, foodweb dynamics; biomarkers; synergistic effects; ocean acidification, ocean anoxia, and climate change 

Professional Experience

  • Research Chemist, U.S. Geological Survey, 2006 – present

  • Mendenhall Postdoctoral Research Fellow, U.S. Geological Survey, Menlo Park, CA 2004–2006

  • Graduate Student Research Assistant, University of California, Santa Cruz, CA 1999–2004

  •  Biology Research Assistant, private biotechnology industry, Silicon Valley, CA 1996–1999

Education and Certifications

  • University of California, San Diego, Biology, B.Sc., 1996

  • University of California, Santa Cruz, Ocean Sciences, Ph.D., 2004

  • U.S. Geological Survey, Pacific Coastal and Marine Geology, Menlo Park, CA, Mendenhall Post-Doctoral Fellow in Organic Geochemistry, 2004–2006

Science and Products

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Diagram showing per-and polyfluoroalkyl substances (PFAS) movement in the environment.

Per-and Polyfluoroalkyl Substances (PFAS) Integrated Science Team

Increasing scientific and public awareness of the widespread distribution of per- and poly-fluoroalkyl substances (PFAS) in U.S. drinking-water supplies, aquatic and terrestrial ecosystems, wildlife, and humans has raised many public health and resource management questions that U.S. Geological Survey's (USGS) science can inform. The USGS Environmental Health Program's PFAS Integrated Science Team...
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology
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Per-and Polyfluoroalkyl Substances (PFAS) Integrated Science Team

Increasing scientific and public awareness of the widespread distribution of per- and poly-fluoroalkyl substances (PFAS) in U.S. drinking-water supplies, aquatic and terrestrial ecosystems, wildlife, and humans has raised many public health and resource management questions that U.S. Geological Survey's (USGS) science can inform. The USGS Environmental Health Program's PFAS Integrated Science Team...
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Two small birds at a bird house

PFAS Transport, Exposure, and Effects

The team is determining the movement and behavior of per- and poly-fluoroalkyl substances (PFAS) from their sources in the environment, as they move through exposure pathways in ecosystems including watersheds and aquifers, their incorporation into food webs, and molecular to population scale effects on fish and wildlife. These studies are accomplished at a variety of spatial scales from regional...
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Ecosystems, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology
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PFAS Transport, Exposure, and Effects

The team is determining the movement and behavior of per- and poly-fluoroalkyl substances (PFAS) from their sources in the environment, as they move through exposure pathways in ecosystems including watersheds and aquifers, their incorporation into food webs, and molecular to population scale effects on fish and wildlife. These studies are accomplished at a variety of spatial scales from regional...
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rails

Ecosystem Effects of Increased Coal Transport Across the Pacific Northwest

Proposed new coal export terminals in Washington and Oregon could increase rail traffic through the Northwest and potentially increase unintended release of coal dust to the environment.
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Forest and Rangeland Ecosystem Science Center, Oregon Water Science Center, Washington Water Science Center
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Ecosystem Effects of Increased Coal Transport Across the Pacific Northwest

Proposed new coal export terminals in Washington and Oregon could increase rail traffic through the Northwest and potentially increase unintended release of coal dust to the environment.
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Osprey on nest

Columbia River Contaminants and Habitat Characterization Study

Fish, wildlife, and human populations along the lower Columbia River are exposed to an ever-growing variety of contaminants as a result of increasing urbanization, industrialization, and agricultural development.
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Oregon Water Science Center
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Columbia River Contaminants and Habitat Characterization Study

Fish, wildlife, and human populations along the lower Columbia River are exposed to an ever-growing variety of contaminants as a result of increasing urbanization, industrialization, and agricultural development.
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Scientist Holding an Adult Pacific Lamprey

Pesticides, Flame Retardants, and Mercury in Tissues from Columbia Basin Pacific Lamprey

Pesticides, flame retardants, and mercury were present in Pacific lampreys (Entosphenus tridentatus) at levels that may be contributing to their overall decline in the Columbia River Basin.These findings are based on the largest available dataset of contaminants measured in lamprey tissues and lamprey habitats by the U.S. Geological Survey (USGS) and the Columbia River Inter-Tribal Fish Commission...
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Ecosystems, Contaminant Biology, Environmental Health Program
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Pesticides, Flame Retardants, and Mercury in Tissues from Columbia Basin Pacific Lamprey

Pesticides, flame retardants, and mercury were present in Pacific lampreys (Entosphenus tridentatus) at levels that may be contributing to their overall decline in the Columbia River Basin.These findings are based on the largest available dataset of contaminants measured in lamprey tissues and lamprey habitats by the U.S. Geological Survey (USGS) and the Columbia River Inter-Tribal Fish Commission...
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A Baseline Assessment of Contaminant Concentrations in Sediment and Biota in Proximity to Coal Transport Tracks in the Pacific Northwest (2014)

This dataset provides baseline concentrations (from 2014) of polycyclic aromatic hydrocarbon (PAH), other aromatic organic compounds, mercury (Hg), and trace metal concentrations in sediment and biota collected from two sites along an existing rail line used for coal transport in the Columbia River Gorge, Washington. For this study, aquatic surface sediments, aquatic insects, and juvenile fish wer
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Washington Water Science Center
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Exploring biophysical linkages between coastal forestry management practices and aquatic bivalve contaminant exposure

Terrestrial land use activities present cross-ecosystem threats to riverine and marine species and processes. Specifically, pesticide runoff can disrupt hormonal, reproductive, and developmental processes in aquatic organisms, yet non-point source pollution is difficult to trace and quantify. In Oregon, U.S.A., state and federal forestry pesticide regulations, designed to meet regulatory water qua
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Water Resources, California Water Science Center, Oregon Water Science Center, Washington Water Science Center

Contaminant concentrations in sediments, aquatic invertebrates, and fish in proximity to rail tracks used for coal transport in the Pacific Northwest: A baseline assessment

Railway transport of coal poses an environmental risk because coal dust contains polycyclic aromatic hydrocarbons (PAHs), mercury (Hg), and other trace metals. In the Pacific Northwest, proposed infrastructure projects could result in an increase in coal transport by train through the Columbia River corridor. Baseline information is needed on current distributions, levels, and spatial patterns of
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Water Resources, Oregon Water Science Center

Critical review: Grand challenges in assessing the adverse effects of contaminants of emerging concern on aquatic food webs

Much progress has been made in the past few decades in understanding the sources, transport, fate, and biological effects of contaminants of emerging concern (CECs) in aquatic ecosystems. Despite these advancements, significant obstacles still prevent comprehensive assessments of the environmental risks associated with the presence of CECs. Many of these obstacles center around the extrapolation o
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Water Resources, Toxic Substances Hydrology, New Jersey Water Science Center, Oregon Water Science Center

Prioritization framework for ranking riverine ecosystem stressors using example sites from the Tualatin River Basin, Oregon

As human populations increase, so does their influence over the environment. Altered terrain, degraded water quality, and threatened or endangered species are all-too-common consequences of a growing anthropogenic influence on the landscape. To help manage these effects, researchers have developed new ways to characterize current environmental conditions and help resource managers seek solutions t
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Water Resources, Oregon Water Science Center

Spatial and temporal variability of contaminants within estuarine sediments and native Olympia oysters: A contrast between a developed and an undeveloped estuary

Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from industrial, municipal, and urban lands, accidental spills, and atmospheric deposition. The diversity of potential sources contributes to the likelihood of contaminated marine waters and sediments
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Water Resources, Washington Water Science Center

Year-round monitoring of contaminants in Neal and Rogers Creeks, Hood River Basin, Oregon, 2011-12, and assessment of risks to salmonids

Pesticide presence in streams is a potential threat to Endangered Species Act listed salmonids in the Hood River basin, Oregon, a primarily forested and agricultural basin. Two types of passive samplers, polar organic chemical integrative samplers (POCIS) and semipermeable membrane devices (SPMDs), were simultaneously deployed at four sites in the basin during Mar. 2011–Mar. 2012 to measure the pr
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Water Resources, Oregon Water Science Center

Reconnaissance of contaminants in larval Pacific lamprey (Entosphenus tridentatus) tissues and habitats in the Columbia River Basin, Oregon and Washington, USA

Pacific lampreys (Entosphenus tridentatus) have resided in the Columbia River Basin for millennia and have great ecological and cultural importance. The role of habitat contamination in the recent decline of the species has rarely been studied and was the main objective of this effort. A wide range of contaminants (115 analytes) was measured in sediments and tissues at 27 sites across a large geog
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Water Resources, Oregon Water Science Center

Contaminants of legacy and emerging concern in largescale suckers (Catostomus macrocheilus) and the foodweb in the lower Columbia River, Oregon and Washington, USA

We investigated occurrence, transport pathways, and effects of polybrominated diphenyl ether (PBDE) flame retardants and other endocrine disrupting chemicals (EDCs) in aquatic media and the foodweb in the lower Columbia River. In 2009 and 2010, foodweb sampling at three sites along a gradient of contaminant exposure near Skamania (Washington), Columbia City (Oregon) and Longview (Washington) inclu
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Ecosystems, Water Resources, Contaminant Biology, Environmental Health Program, Fisheries Program, Columbia Environmental Research Center, Oregon Water Science Center, Western Fisheries Research Center, Columbia River Research Laboratory (CRRL)

Sedimentary organic biomarkers suggest detrimental effects of PAHs on estuarine microbial biomass during the 20th century in San Francisco Bay, CA, USA

Hydrocarbon contaminants are ubiquitous in urban aquatic ecosystems, and the ability of some microbial strains to degrade certain polycyclic aromatic hydrocarbons (PAHs) is well established. However, detrimental effects of petroleum hydrocarbon contamination on nondegrader microbial populations and photosynthetic organisms have not often been considered. In the current study, fatty acid methyl est
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Water Resources, Oregon Water Science Center

Health status of Largescale Sucker (Catostomus macrocheilus) collected along an organic contaminant gradient in the lower Columbia River, Oregon and Washington, USA

The health of Largescale Sucker (Catostomus macrocheilus) in the lower Columbia River (USA) was evaluated using morphometric and histopathological approaches, and its association with organic contaminants accumulated in liver was evaluated in males. Fish were sampled from three sites along a contaminant gradient In 2009, body length and mass, condition factor, gonadosomatic index, and hematocrit w
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Cooperative Research Units

Spatial and temporal trends in occurrence of emerging and legacy contaminants in the Lower Columbia River 2008-2010

The Lower Columbia River in Oregon and Washington, USA, is an important resource for aquatic and terrestrial organisms, agriculture, and commerce. An 86-mile stretch of the river was sampled over a 3 year period in order to determine the spatial and temporal trends in the occurrence and concentration of water-borne organic contaminants. Sampling occurred at 10 sites along this stretch and at 1 sit
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Ecosystems, Contaminant Biology, Environmental Health Program, Columbia Environmental Research Center

Assessing reproductive and endocrine parameters in male largescale suckers (Catostomus macrocheilus) along a contaminant gradient in the lower Columbia River, USA

Persistent organochlorine pollutants such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p′-DDE), and polybrominated diphenyl ethers (PBDEs) are stable, bioaccumulative, and widely found in the environment, wildlife, and the human population. To explore the hypothesis that reproduction in male fish is associated with environmental exposures in the lower Columbia River (LC
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Ecosystems, Wetland and Aquatic Research Center

Pre-USGS Publications

Nilsen, E.B., and Delaney, M.L.:2005, Factors influencing the biogeochemistry of sedimentary carbon and phosphorus in the Sacramento-San Joaquin Delta: Estuaries (2005) 28, p. 653. doi:10.1007/BF02732904
Nilsen, E. B., L. D. Anderson, and M. L. Delaney, 2003, Paleoproductivity, nutrient burial, climate change and the carbon cycle in the western equatorial Atlantic across the Eocene/Oligocene boundary: Paleoceanography, 18, 1057, doi:10.1029/2002PA000804, 3.
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Potentially Harmful Levels of Contaminants Found in Fish in the Columbia River

A newly published scientific study discovered that some resident fish in the lower Columbia River, namely largescale suckers, contain chemicals that...
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