Johanna Kraus, Ph.D.


Johanna Kraus is a research ecologist whose research focuses on the food web implications of organismal and contaminant transfer across ecosystem boundaries. She started with the USGS in 2011 as a Mendenhall Research Fellow studying the effects of stream metal pollution on aquatic insect emergence, contaminant flux to riparian spiders and use of terrestrial subsidies by stream fish in Colorado Rocky Mountain streams. Previous to that, she completed a research post-doctoral study at Virginia Commonwealth University studying effects of habitat selection on aquatic-terrestrial linkages in experimental pond systems and collaborated internationally to study effects of dams on downstream spider communities in Japanese streams as part of a NSF/JSPS funded EAPSI fellowship. She currently is a member of the Aquatic Ecology and Contaminants Team at Fort Collins Science Center and the Toxic Substances Hydrology Program's Pesticide Team investigating various human impacts to aquatic and riparian systems using field studies, manipulative experiments and modeling.     


    • Ph.D., Biology, University of Virginia, 2006
    • B.A., Biology, Brown University, (honors, magna cum laude), 1998

    Professional Appointments

    • 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
    • National Science Foundation Graduate Research Fellow, 2002-2005  
    • Teaching Assistant, University of Virginia, 2002-2005  
    • Presidential Fellow, University of Virginia, 2000

    Projects include

    • Food web dynamics in mineralized streams and riparian ecosystems 

    Trace-metal contamination of aquatic ecosystems is a major health and environmental concern globally, leading to alterations of aquatic communities, decreased fisheries and bioaccumulation in higher trophic levels. In the Rocky Mountains, we are examining the role of trace metal pollution in determining importance of resource subsidies (adult aquatic insects and terrestrial inputs) for riparian and aquatic predators, and the flux of metals through these foods webs.

    • Riparian indicators of contaminant exposure at Great Lakes Areas of Concern (AOC's) 

    We are investigating contaminant flux from aquatic to nearby terrestrial shoreline habitats. In particular we use riparian spiders to characterize contaminant at these sites and to evaluate the effectiveness of their remediation.

    • Current-use pesticides in the Chesapeake Bay Watershed and Prairie Potholes Region 

    These projects investigate the uptake and export of current-use and legacy pesticides from the aquatic environment in adult aquatic insects that emerge from agriculturally impacted rivers and wetland ecosystems in Virginia and North Dakota.