MP4 Toxic Effects of Pesticide Mixtures
204 Oregon Ballroom
1:20 PM - 4:40 PM, Monday
() Experimental examination of amphibians in complex chemical environments in mesocosms and golf course ponds.
Boone, Michelle1, 1 Miami University, Oxford, OH, USA
ABSTRACT- Agricultural areas and heavily managed green spaces (like golf courses) often include wetlands or influence nearby wetlands that are utilized by amphibians for larval growth and development. My studies are designed to determine the effects of multiple chemical stressors that may contribute to worldwide amphibian population declines, and to examine the risk of chemical mixtures to amphibian communities. In field studies, I have examined the interactive effects of the insecticide carbaryl with ammonium nitrate fertilizer and with the herbicide atrazine on larval anurans and salamanders, and their plankton resources. Additionally, I have reared amphibians in golf course ponds to examine how complex chemical environments may influence amphibians in the field. Generally, we found that singular chemical stressors had a stimulatory response, but that the combination of two or more stress had negative effects on time, size, and survival to metamorphosis. This suggests that even sublethal levels of chemical contaminants in combination may negatively impact amphibian communities in ways not predictable from single chemical studies or by examining the effects of the chemicals on their food resources alone. We also found that amphibians reared in golf course pond environments were smaller at metamorphosis and had lower survival compared to control ponds, suggesting that complex chemical mixtures may collectively have negative effects on amphibians when single chemicals would not. My studies collectively suggest that multiple chemical contaminants could negatively affect amphibian communities and lead to population declines.
Key words: chemical mixtures, amphibian, synergistic interactions, metamorphosis