Dr. Johanna M. Kraus is a Research Ecologist at the Columbia Environmental Research Center.
She studies effects of anthropogenic stressors on food webs, biodiversity and environmental health in aquatic and terrestrial ecosystems. She began her career with the USGS in 2011 researching how trace metals from acid rock drainage impact adult aquatic insect emergence and contaminant flux to terrestrial insectivores near mountain streams. Since then, her research has uncovered when and where contaminants may impact aquatic and terrestrial food webs using large empirical field studies, laboratory manipulations and conceptual modelling. Dr. Kraus received her B.A. in Biology from Brown University and Ph.D. in Biology from the University of Virginia.
Professional Experience
Research Ecologist, U.S. Geological Survey, 2016 - present
Mendenhall Research Fellow, U.S. Geological Survey 2011- 2015
Post-doctoral Researcher, Biology, Virginia Commonwealth University, 2007-2010
Visiting Assistant Professor, Biology, Washington and Lee University, 2006-2007
National Science Foundation EAPSI Fellow, Japan, 2006
Education and Certifications
Ph.D., Biology, University of Virginia, 2006
B.A., Biology, Brown University, honors, magna cum laude, 1998
Science and Products
Conceptual Model Developed to Understand Contaminant Pathways between Aquatic and Terrestrial Ecosystems
Trace Metal Mobility in the Yellow Pine Mining District, Idaho
Aquatic Ecology and Contaminants
Pesticides in the Prairie Pothole Region
Effects of Contaminants on Linked Aquatic and Terrestrial Food Webs
Images and Identifications of Wild Bees Collected in Eastern Iowa, 2019
Total mercury, methylmercury, and isotopic composition in various life stages of boreal chorus frogs (Pseudacris maculata) at two subalpine ponds in the Rocky Mountains, CO, USA, 2015
Pesticide residues in passive samplers and bee tissue from Conservation Reserve Program fields across an agricultural gradient in eastern Iowa, USA, 2019
Mercury concentrations, isotopic composition, biomass, and taxonomy of stream and riparian organisms in the vicinity of Yellow Pine, Idaho, 2015-2016.
Trace metals in water and biota in and near headwater streams in the Colorado Mineral Belt
Polychlorinated biphenyl concentrations and lipid content in riparian spiders at the Ashtabula River Area of Concern, USA
Zinc concentrations and isotopic signatures of an aquatic insect (mayfly, Baetis tricaudatus)
Complex life histories alter patterns of mercury exposure and accumulation in a pond-breeding amphibian
Wild bee exposure to pesticides in conservation grasslands increases along an agricultural gradient: A tale of two sample types
Increased mercury and reduced insect diversity in linked stream-riparian food webs downstream of a historical mercury mine
Contaminant fluxes across ecosystems mediated by aquatic insects
Insect-mediated contaminant flux at the land–water interface: Are ecological subsidies driving exposure or is exposure driving subsidies?
Cross-ecosystem fluxes of pesticides from prairie wetlands mediated by aquatic insect emergence: Implications for terrestrial insectivores
Variation in metal concentrations across a large contamination gradient is reflected in stream but not linked riparian food webs
Synthesis: A framework for predicting the dark side of ecological subsidies
Metamorphosis and the impact of contaminants on ecological subsidies
Introduction: Ecological subsidies as a framework for understanding contaminant fate, exposure, and effects at the land-water interface
Cross-ecosystem linkages and trace metals at the land-water interface
Applying the ecology of aquatic–terrestrial linkages to freshwater and riparian management
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
Conceptual Model Developed to Understand Contaminant Pathways between Aquatic and Terrestrial Ecosystems
A conceptual model, based on contaminant properties and ecotoxicological principles, was developed to understand the transfer of contaminants from aquatic to terrestrial ecosystems and the effects of various classes of contaminants on terrestrial insectivores living near contaminated freshwaters.Trace Metal Mobility in the Yellow Pine Mining District, Idaho
The study objective is to conduct an integrated, interdisciplinary study on source areas, biogeochemical transformations, and physical and biological pathways for trace metal transport in a tributary of the Snake River watershed, focusing on the Sugar Creek watershed. The historical Cinnabar mercury mine site is at the headwaters of Cinnabar Creek, a tributary to Sugar Creek. This integrated...Aquatic Ecology and Contaminants
The Aquatic Ecology and Contaminants Team investigates critical ecological processes operating in aquatic and riparian ecosystems and how these processes are affected by human activities. We address questions through a combination of field studies, laboratory experiments, and modeling, while working at multiple levels of biological organization from cells through ecosystems. Topics include land...Pesticides in the Prairie Pothole Region
Wetlands of the northern Great Plains are crucial feeding grounds for migrating birds and waterfowl embedded in an agricultural landscape. Land use and hydrology can affect adult aquatic insects – crucial prey for critically declining populations of insectivorous birds. Current studies focus on effects of current-use pesticides on adult aquatic insects to inform decision making about contaminants...Effects of Contaminants on Linked Aquatic and Terrestrial Food Webs
Most aquatic insects live in fresh water as larvae and move to land as flying adults to complete their life cycle. Although often ignored, the emergence of adults can transfer the effects of contamination from aquatic to terrestrial ecosystems as the adults are eaten by predators such as spiders, birds, and bats. - Data
Images and Identifications of Wild Bees Collected in Eastern Iowa, 2019
Bees were collected in 24 fields across eastern Iowa in summer 2019. This data collection was part of a pesticide study funded by the USGS Ecosystems Mission Area- Environmental Health Program. Bees were collected using the sweep net method and then were immediately placed on dry ice in the field. Bees were kept frozen to prevent degradation. In the lab, each wild bee was photographed from one orTotal mercury, methylmercury, and isotopic composition in various life stages of boreal chorus frogs (Pseudacris maculata) at two subalpine ponds in the Rocky Mountains, CO, USA, 2015
Mercury is an atmospherically transported contaminant found even in relatively pristine habitats. Once accumulated at the base of the food web, mercury can move between animals that are linked trophically. Pond-breeding amphibians may be particularly important vectors of mercury flux from remote freshwater to terrestrial systems because they feed on algae and detritus as tadpoles and metamorphosePesticide residues in passive samplers and bee tissue from Conservation Reserve Program fields across an agricultural gradient in eastern Iowa, USA, 2019
This data release includes sampling location, pesticide concentrations in passive samplers (silicone bands) and bees foraging in Conservation Reserve Program fields. Sampling took place during July and August of 2019. Fields were located on private land managed for the U.S. Department of Agriculture Conservation Reserve Program in eastern central Iowa, U.S.A.Mercury concentrations, isotopic composition, biomass, and taxonomy of stream and riparian organisms in the vicinity of Yellow Pine, Idaho, 2015-2016.
This data release includes sampling location data; field-collected stream attribute data; laboratory-analyzed chemistry concentrations (total mercury, methyl mercury) and isotopic composition (total mercury, carbon, and nitrogen) for stream biota (seston, periphyton, benthic insects, emerging adult insects, riparian spiders, and fish); density, body length, and taxonomic information for benthic inTrace metals in water and biota in and near headwater streams in the Colorado Mineral Belt
This data release includes sampling location data, field-collected water chemistry data, cation and anion concentration data for water and tissues of submerged aquatic vegetation, aquatic insect larvae, adult aquatic insects and riparian spiders from 35 first- and second-order sub-alpine streams that ranged over several orders of magnitude in metal concentrations but were similar in elevation, geoPolychlorinated biphenyl concentrations and lipid content in riparian spiders at the Ashtabula River Area of Concern, USA
We measured polychlorinated biphenyl (PCB) concentrations in two taxa of riparian spiders from nine sites in 2011 at the Ashtabula River Area of Concern. We analyzed the extracts for 122 congeners following EPA method SW846 Method 8270D using gas chromatography mass spectrometry in the selective ion monitoring (SIM) mode. All target compounds were quantified using the method of internal standards,Zinc concentrations and isotopic signatures of an aquatic insect (mayfly, Baetis tricaudatus)
Insect metamorphosis often results in substantial chemical changes that can fractionate isotopes and alter contaminant concentrations. We exposed larval mayflies (Baetis tricaudatus) to an aqueous zinc gradient (3-340 g Zn/l) and measured the change in zinc tissue concentrations at different stages of metamorphosis. We also measured changes in stable isotopes (δ15N and δ13C) in unexposed B. tricau - Multimedia
- Publications
Filter Total Items: 29
Complex life histories alter patterns of mercury exposure and accumulation in a pond-breeding amphibian
Quantifying how contaminants change across life cycles of species that undergo metamorphosis is critical to assessing organismal risk, particularly for consumers. Pond-breeding amphibians can dominate aquatic animal biomass as larvae and are terrestrial prey as juveniles and adults. Thus, amphibians can be vectors of mercury exposure in both aquatic and terrestrial food webs. However, it is stillAuthorsFreya Elizabeth Rowland, Erin L. Muths, Collin Eagles-Smith, Craig A. Stricker, Johanna M. Kraus, Rachel A. Harrington, David WaltersWild bee exposure to pesticides in conservation grasslands increases along an agricultural gradient: A tale of two sample types
Conservation efforts have been implemented in agroecosystems to enhance pollinator diversity by creating grassland habitat, but little is known about the exposure of bees to pesticides while foraging in these grassland fields. Pesticide exposure was assessed in 24 conservation grassland fields along an agricultural gradient at two time points (July and August) using silicone band passive samplersAuthorsMichelle Hladik, Johanna M. Kraus, Cassandra Smith, Mark W. Vandever, Dana W. Kolpin, Carrie E Givens, Kelly SmallingIncreased mercury and reduced insect diversity in linked stream-riparian food webs downstream of a historical mercury mine
Historical mining left a legacy of abandoned mines and waste rock in remote headwaters of major river systems in the western United States. Understanding the influence of these legacy mines on culturally and ecological important downstream ecosystems is not always straight-forward because of elevated natural levels of mineralization in mining-impacted watersheds. To test the ecological effects ofAuthorsJohanna M. Kraus, JoAnn Holloway, Michael Pribil, Ben N. Mcgee, Craig A. Stricker, Danny Rutherford, Andrew S. ToddContaminant fluxes across ecosystems mediated by aquatic insects
Metals and organic contaminants in aquatic systems affect the coupling of aquatic and terrestrial ecosystems through two pathways: contaminant-induced effects on insect emergence and emergence-induced contaminant transfer. Consequently, the impact of aquatic contaminants on terrestrial ecosystems can be driven by modifications in the quantity and quality of adult aquatic insects serving as prey orAuthorsMirco Bundschuh, Sebastian Pietz, Alexis P. Roodt, Johanna M. KrausInsect-mediated contaminant flux at the land–water interface: Are ecological subsidies driving exposure or is exposure driving subsidies?
Chemical contamination of freshwaters is a global problem. In the United States alone, millions of kilometers of rivers and hectares of lakes and wetlands are impaired from contamination by chemicals including mercury, pesticides, polychlorinated biphenyls (PCBs), and trace metals (US Environmental Protection Agency, 2017). Efforts to mitigate the risks of contamination have largely focused on aquAuthorsJohanna M. Kraus, Jeff S. Wesner, David WaltersCross-ecosystem fluxes of pesticides from prairie wetlands mediated by aquatic insect emergence: Implications for terrestrial insectivores
Contaminants alter the quantity and quality of insect prey available to terrestrial insectivores. In agricultural regions, the quantity of aquatic insects emerging from freshwaters can be impacted by insecticides originating from surrounding croplands. We hypothesized that, in such regions, adult aquatic insects could also act as vectors of pesticide transfer to terrestrial food webs. To estimateAuthorsJohanna M. Kraus, Kathryn Kuivila, Michelle Hladik, Neil Shook, David M. Mushet, Kelen Dowdy, Rachel HarringtonVariation in metal concentrations across a large contamination gradient is reflected in stream but not linked riparian food webs
Aquatic insects link food web dynamics across freshwater-terrestrial boundaries and subsidize terrestrial consumer populations. Contaminants that accumulate in larval aquatic insects and are retained across metamorphosis can increase dietary exposure for riparian insectivores. To better understand potential exposure of terrestrial insectivores to aquatically-derived trace metals, metal concentratiAuthorsJohanna M. Kraus, Richard Wanty, Travis S. Schmidt, David Walters, Ruth E. WolfSynthesis: A framework for predicting the dark side of ecological subsidies
In this chapter, we synthesize the state of the science regarding ecological subsidies and contaminants at the land-water interface and suggest research and management approaches for linked freshwater-terrestrial ecosystems. Specifically, we focus on movements of animals with complex life histories and the detrital inputs associated with animal and plant matter delivered to freshwaters. We presentAuthorsJohanna M. Kraus, Jeff Wessner, David WaltersMetamorphosis and the impact of contaminants on ecological subsidies
Animals with complex life histories such as aquatic insects and amphibians link freshwater and terrestrial ecosystems when they transition from water to land during development. This transition requires metamorphosis from juvenile to adult life stages. Metamorphosis is a stressful and ecologically sensitive life history event. Exposure to contaminants during juvenile development (before or duringAuthorsJeff Wesner, Johanna M. Kraus, Brianna L. Henry, Jacob KerbyIntroduction: Ecological subsidies as a framework for understanding contaminant fate, exposure, and effects at the land-water interface
Ecologists have long recognized that ecological subsidies (the flow of organic matter, nutrients, and organisms between ecosystems) can strongly affect ecosystem processes and community structure in the recipient ecosystem. Animal movements, organic matter flows, and food web dynamics between linked aquatic and terrestrial systems can also influence contaminant fate, exposure, and effects at the lAuthorsDavid Walters, Johanna M. Kraus, Marc A. MillsCross-ecosystem linkages and trace metals at the land-water interface
At low concentrations, trace metals are critical for sustaining life on Earth. However, at high concentrations, they become a global contaminant with particularly strong effects on freshwater communities. These effects can propagate to terrestrial ecosystems in part by altering production and community structure of adult aquatic insect emergence and aquatic insect-mediated metal fluxes to terrestrAuthorsJohanna M. Kraus, Justin F. PomeranzApplying the ecology of aquatic–terrestrial linkages to freshwater and riparian management
Global stressors such as climate change, invasive species, urbanization, agricultural practices, and pollution can alter aquatic resource subsidies to terrestrial consumers. The effects of these stressors on timing, quality, and quantity of aquatic subsidies, such as adult aquatic insects, to birds, herpetofauna, and mammals, have large implications for wildlife management (Baxter et al. 2004, SauAuthorsJohanna M. KrausNon-USGS Publications**
Wanty R.B., L.S. Balistrieri, J.S. Wesner, D.M. Walters, T.S. Schmidt, F. Podda, G. De Giudici, C.A. Stricker, J.M. Kraus, P. Lattanzi, R.E. Wolf, R. Cidu. 2015. Isotopic insights into biological regulation of zinc in contaminated systems. 11th Applied Isotope Geochemistry Conference, AIG-11 BRGM. Procedia Earth and Planetary Science 13: 60-63.Vonesh, J.R., J.M. Kraus. 2009. Pesticide alters habitat selection and aquatic community composition. Oecologia 160: 379–385.Vonesh, J.R., J.M. Kraus, S. Rosenberg, and J.M. Chase. 2009. Predator effects on aquatic community assembly: disentangling the roles of habitat selection and post-colonization processes. Oikos 118: 1219-1229.Ahrens L., and J.M. Kraus. 2006. Wolf spider (Araneae: Lycosidae) movement along a pond-forest boundary. Journal of Arachnology 34: 532-539.Kraus J.M., and D. H. Morse. 2005. Seasonal habitat shift in an intertidal wolf spider: proximal cues associated with migration and substrate preference. Journal of Arachnology 33:110–123.Deyrup M., J.M. Kraus, and T. Eisner. 2004. A Florida caterpillar and other arthropods inhabiting the webs of a subsocial spider (Lepidoptera: Pyralidae; Araneida: Theridiidae). Florida Entomologist 87:554-558.Church S.A.P., J.M. Kraus, J.C. Mitchell, D.R. Church, and D.R. Taylor. 2003. Evidence for multiple pleistocene refugia in the postglacial expansion of the eastern tiger salamander, Ambystoma tigrinum tigrinum. Evolution 57: 372–383.**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.
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