Abstract:
Chemical contamination of roadside vernal breeding pools threatens amphibian abundance and diversity. Deicing compounds from roads in northern latitudes are the primary cause of contamination in spring, coinciding with amphibian breeding. Triclosan, a personal care product, also negatively affects amphibians. My objective was to study the acute toxicity of deicers and triclosan on six species of Nova Scotian amphibian larvae: spotted salamanders (Ambystoma maculatum), wood frogs (Lithobates sylvaticus), spring peepers (Pseudacris crucifer), mink frogs (Lithobates septentrionalis), green frogs (Lithobates clamitans), and American toads (Anaxyrus americanus). Median lethal concentrations (LC[subscript 50]) of all chemicals varied among species, but early-breeding species were consistently most sensitive. Early life stages were most sensitive to all chemicals, and median LC[subscript 50] values increased throughout larval development. Larvae exposed at 22˚C were more sensitive than those exposed at 12˚C. Results indicate that synergism between environmental and developmental factors can lead to detrimental effects on amphibians.