Meeting Abstract
Amphibian populations have been declining around the World for several decades, with one of the primary reasons being environmental pollution. One source of pollution is agricultural activity, since pesticide and chemical fertilizer run-off can enter natural aquatic environments. We used the African clawed frog Xenopus laevis as our model organism to examine the effect of pesticides (nonylphenol) and fertilizers (ammonium nitrate) on developing amphibians. We hypothesized that ammonium nitrate and nonylphenol will interfere with development when embryos are exposed to sub-lethal concentrations, and that the two chemicals in combination will have an exaggerated affect compared to each chemical alone. Embryos were exposed to a range of concentrations of ammonium nitrate (0mg/L, 12.5mg/L, 25mg/L, and 50mg/L) and nonylphenol (5μM, 10μM, and 20 μM) both independently and in combination and development was monitored by examining stage specific morphology and by measuring total body length and head width. The mortality observed varied between the concentrations but when exposed to higher concentrations the embryos had delayed growth and were much smaller compared with the control and lower concentrations of ammonium nitrate. This lab study modeled a situation that can occur in natural ecosystems, and demonstrated how commonly used chemicals can potentially impact amphibian populations in the wild.
