Abstract:
Chemical contamination is a primary factor contributing to worldwide amphibian
declines. Road salt is a major pollutant producing elevated chloride concentrations in
freshwater systems. Additionally, ferrocyanide anti-caking agents are released from road
salt and effects on the environment are poorly understood. Amphibians exhibit low
tolerance to salt. Our purpose is to investigate chronic, sub-lethal NaCl exposure on
developmental amphibian stages and determine acute toxicity of cyanide. Chronic
toxicity experiments at environmentally significant salt concentrations were conducted on
larvae of three species and embryos of five species in the laboratory. Species tested were
spotted salamanders, American toads, spring peepers, green frogs and wood frogs.
Cyanide acute toxicity experiments were performed on the five species. Chronic salt
exposure reduced hatching, increased mortality, and induced developmental and
behavioural anomalies. Median lethal concentration values were calculated from cyanide
acute toxicity experiments. Results indicate that the chronic effects can inflict detrimental
consequences to amphibian populations.