Paper No. JAWRA-11-0018-P of the Journal of the American Water Resources Association (JAWRA). Discussions are open until six months from print publication.
Exposure Times to the Spring Atrazine Flush Along a Stream-Reservoir System1
Version of Record online: 9 MAR 2012
© 2012 American Water Resources Association
JAWRA Journal of the American Water Resources Association
Volume 48, Issue 3, pages 616–634, June 2012
How to Cite
Stoeckel, J. A., Morris, J., Ames, E., Glover, D. C., Vanni, M. J., Renwick, W. and González, M. J. (2012), Exposure Times to the Spring Atrazine Flush Along a Stream-Reservoir System. JAWRA Journal of the American Water Resources Association, 48: 616–634. doi: 10.1111/j.1752-1688.2011.00633.x
- Issue online: 1 JUN 2012
- Version of Record online: 9 MAR 2012
- Received February 10, 2011; accepted December 12, 2011.
- spring flush;
Stoeckel, James A., Jade Morris, Elizabeth Ames, David C. Glover, Michael J. Vanni, William Renwick, and María J. González, 2012. Exposure Times to the Spring Atrazine Flush Along a Stream-Reservoir System. Journal of the American Water Resources Association (JAWRA) 48(3): 616-634. DOI: 10.1111/j.1752-1688.2011.00633.x
Abstract: We used enzyme-linked immunosorbent assay to examine reservoir-mediated shifts in spring to fall exposure of aquatic organisms to the spring atrazine pulse over four years in a Midwestern stream-reservoir system. Peak atrazine concentrations in the major inflowing stream exceeded 10 μg/l in all four years. The reservoir had a beneficial effect in two of four years by diluting atrazine below the 10 μg/l threshold. However, during the other two years, exposure times above 10 μg/l were approximately doubled in the reservoir compared to the major inflowing stream. Thresholds of 3 and 5 μg/l were exceeded during all four years in the reservoir. The uplake and downlake reservoir sites were four to five times more likely to exceed these thresholds and aquatic organisms were subjected to longer exposure times above these thresholds compared to the inflowing stream. Release of elevated atrazine concentrations from the reservoir extended exposure times in the outflowing stream. This effect was most pronounced just below the dam. Aquatic organisms upstream of the reservoir were most likely to experience acute exposures whereas organisms within and immediately downstream of the reservoir were more likely to experience chronic exposures. The ubiquity of reservoirs and the annual spring herbicide flush highlight the importance of considering the presence and relative location of reservoirs when assessing risk to aquatic communities as well as locations of drinking water intakes.