About the Authors

Amy E. George

ageorge@usgs.gov

Affiliation U.S. Geological Survey—Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO 65201, United States of America

Duane C. Chapman

Affiliation U.S. Geological Survey—Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO 65201, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: AEG DCC. Performed the experiments: AEG DCC. Analyzed the data: AEG DCC. Contributed reagents/materials/analysis tools: AEG DCC. Wrote the paper: AEG DCC.