Johanna Kraus, PhD
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
Mercury concentrations, isotopic composition, biomass, and taxonomy of stream and riparian organisms in the vicinity of Yellow Pine, Idaho, 2015-2016. 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...
Adult aquatic insect emergence, insect pesticide concentrations and water chemistry of wetlands in the Prairie Pothole Region, North Dakota, USA, 2015-16 (ver. 1.1, August 2025) Adult aquatic insect emergence, insect pesticide concentrations and water chemistry of wetlands in the Prairie Pothole Region, North Dakota, USA, 2015-16 (ver. 1.1, August 2025)
This data release includes sampling location data, field-collected wetland attribute data, field-collected water chemistry data, laboratory-processed water chemistry data (anions, cations, alkalinity, nutrients, chlorophyll a concentrations, dissolved organic carbon, and specific ultraviolet absorbance, pesticide concentrations), dry mass of adult aquatic insects emerging from the...
Trace metals in water and biota in and near headwater streams in the Colorado Mineral Belt Trace 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...
Polychlorinated biphenyl concentrations and lipid content in riparian spiders at the Ashtabula River Area of Concern, USA Polychlorinated 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...
Zinc concentrations and isotopic signatures of an aquatic insect (mayfly, Baetis tricaudatus) 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...
Filter Total Items: 36
Ecological harm and economic damages of chemical contamination to linked aquatic-terrestrial food webs: A study-design tool for practitioners Ecological harm and economic damages of chemical contamination to linked aquatic-terrestrial food webs: A study-design tool for practitioners
Contamination of aquatic ecosystems can have cascading effects on terrestrial consumers by altering the availability and quality of aquatic insect prey. Comprehensive assessment of these indirect food-web effects of contaminants on natural resources and their associated services necessitates using both ecological and economic tools. In the present study we present an aquatic-terrestrial...
Authors
Johanna M. Kraus, Kristin Skrabis, Serena Ciparis, John Isanhart, Aleshia Kenney, Jo Ellen Hinck
Complex life histories alter patterns of mercury exposure and accumulation in a pond-breeding amphibian 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...
Authors
Freya Elizabeth Rowland, Erin L. Muths, Collin A. Eagles-Smith, Craig A. Stricker, Johanna M. Kraus, Rachel A. Harrington, David Walters
Wild bee exposure to pesticides in conservation grasslands increases along an agricultural gradient: A tale of two sample types Wild 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...
Authors
Michelle L. Hladik, Johanna M. Kraus, Cassandra Smith, Mark W. Vandever, Dana W. Kolpin, Carrie E. Givens, Kelly L. Smalling
Increased mercury and reduced insect diversity in linked stream-riparian food webs downstream of a historical mercury mine Increased 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...
Authors
Johanna M. Kraus, JoAnn M. Holloway, Michael Pribil, Ben N. Mcgee, Craig A. Stricker, Danny Rutherford, Andrew S. Todd
Contaminant fluxes across ecosystems mediated by aquatic insects Contaminant 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...
Authors
Mirco Bundschuh, Sebastian Pietz, Alexis P. Roodt, Johanna M. Kraus
Insect-mediated contaminant flux at the land–water interface: Are ecological subsidies driving exposure or is exposure driving subsidies? Insect-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...
Authors
Johanna M. Kraus, Jeff S. Wesner, David Walters
Non-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.
Science and Products
Mercury concentrations, isotopic composition, biomass, and taxonomy of stream and riparian organisms in the vicinity of Yellow Pine, Idaho, 2015-2016. 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...
Adult aquatic insect emergence, insect pesticide concentrations and water chemistry of wetlands in the Prairie Pothole Region, North Dakota, USA, 2015-16 (ver. 1.1, August 2025) Adult aquatic insect emergence, insect pesticide concentrations and water chemistry of wetlands in the Prairie Pothole Region, North Dakota, USA, 2015-16 (ver. 1.1, August 2025)
This data release includes sampling location data, field-collected wetland attribute data, field-collected water chemistry data, laboratory-processed water chemistry data (anions, cations, alkalinity, nutrients, chlorophyll a concentrations, dissolved organic carbon, and specific ultraviolet absorbance, pesticide concentrations), dry mass of adult aquatic insects emerging from the...
Trace metals in water and biota in and near headwater streams in the Colorado Mineral Belt Trace 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...
Polychlorinated biphenyl concentrations and lipid content in riparian spiders at the Ashtabula River Area of Concern, USA Polychlorinated 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...
Zinc concentrations and isotopic signatures of an aquatic insect (mayfly, Baetis tricaudatus) 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...
Filter Total Items: 36
Ecological harm and economic damages of chemical contamination to linked aquatic-terrestrial food webs: A study-design tool for practitioners Ecological harm and economic damages of chemical contamination to linked aquatic-terrestrial food webs: A study-design tool for practitioners
Contamination of aquatic ecosystems can have cascading effects on terrestrial consumers by altering the availability and quality of aquatic insect prey. Comprehensive assessment of these indirect food-web effects of contaminants on natural resources and their associated services necessitates using both ecological and economic tools. In the present study we present an aquatic-terrestrial...
Authors
Johanna M. Kraus, Kristin Skrabis, Serena Ciparis, John Isanhart, Aleshia Kenney, Jo Ellen Hinck
Complex life histories alter patterns of mercury exposure and accumulation in a pond-breeding amphibian 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...
Authors
Freya Elizabeth Rowland, Erin L. Muths, Collin A. Eagles-Smith, Craig A. Stricker, Johanna M. Kraus, Rachel A. Harrington, David Walters
Wild bee exposure to pesticides in conservation grasslands increases along an agricultural gradient: A tale of two sample types Wild 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...
Authors
Michelle L. Hladik, Johanna M. Kraus, Cassandra Smith, Mark W. Vandever, Dana W. Kolpin, Carrie E. Givens, Kelly L. Smalling
Increased mercury and reduced insect diversity in linked stream-riparian food webs downstream of a historical mercury mine Increased 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...
Authors
Johanna M. Kraus, JoAnn M. Holloway, Michael Pribil, Ben N. Mcgee, Craig A. Stricker, Danny Rutherford, Andrew S. Todd
Contaminant fluxes across ecosystems mediated by aquatic insects Contaminant 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...
Authors
Mirco Bundschuh, Sebastian Pietz, Alexis P. Roodt, Johanna M. Kraus
Insect-mediated contaminant flux at the land–water interface: Are ecological subsidies driving exposure or is exposure driving subsidies? Insect-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...
Authors
Johanna M. Kraus, Jeff S. Wesner, David Walters
Non-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.