Effects of Petroleum Distillates on Amphibian Development.

摘要

Petroleum distillates are widely used as an energy source and the extraction and disposal of these chemicals are done with little consideration of their effects on aquatic environments. Amphibians are considered excellent ecological indicators but little research has examined effects of petroleum distillates on aquatic species. I evaluated the lethal and sublethal effects on larval amphibians with exposure to petroleum distillates associated with various venues of pollution including hydraulic fracturing. I selected three petroleum distillates (kerosene, oil, and unleaded gasoline) that are known to have negative effects on aquatic organisms and are similar to the common constituents of mixtures used in hydraulic fracturing fluid. I examined effects of acute exposure to the water-soluble fraction of each of three distillates at four concentrations in four species: Anaxyrus americanus, Lithobates sphenocephalus, Hyla chrysoscelis, and Ambystoma maculatum. Specifically, I evaluated survival, level of narcosis, and swim time in response to a stimulus over a 72-hour period. I identified a significant distillate by time effect on response to stimulus and a distillate by concentration effect in all species except Hyla chrysoscelis. Anaxyrus americanus and Hyla chrysoscelis exhibited a significant three-way interaction among distillate, time, and concentration (p<0.001). Gasoline revealed the greatest lethal impact and oil caused the lowest levels of narcosis. My results suggest that petroleum distillate exposure through open waste ponds or leakage of petroleum distillates is a concern for amphibians. Improved knowledge of the petroleum distillates and their effects on wildlife are needed to develop policies that balance preservation of the environment with human energy needs.