M9 PM Multiple Stressors in Amphibian and Reptile Ecotoxicology
Monday, 14 November 2005: 1:50 PM - 5:30 PM in 339-340

(BOO-1117-827118) Examining the Role of Contaminants in the Sensitivity of Amphibians to a Pathogen.

Boone, M¹, ¹ Miami University, Oxford, OH, USA

ABSTRACT- Reports of amphibian declines have not been clearly attributed to any single cause and recently many researchers have suggested that multiple sublethal stressors may contribute to population declines. I have examined the effects of sublethal exposure to a fertilizer, insecticide, or herbicide on susceptibility of tadpoles and embryos to a widespread pathogenic fungus, Saprolegnia ferax, in experimental laboratory and field studies using spotted salamanders, gray treefrogs, and American toads. In the laboratory, eggs were exposed to no, low, or high levels of S. ferax and the presence or absence of an expected environmental concentration of a contaminant. In field studies, tadpoles were exposed to the presence or absence of a contaminant (ammonium nitrate) and five levels of S. ferax to examine if the chemical exposure influenced susceptibility or if the stressors interacted synergistically. Preliminary evidence in the laboratory and field suggest that presence of chemical contamination can increase the susceptibility of eggs and tadpoles to infection, which could contribute to juvenile recruitment into the breeding population and potentially to population declines.

Key words: Saprolegnia ferax, fertilizer, amphibian, multiple stressors