Short term effects of military fog oil on the fountain darter (Etheostoma fonticola)
Fog oil is used by the US military during training exercises to produce obscurant smoke. The smoke enters aquatic systems by settling as an oily residue on water surfaces. Its effects on aquatic biota are largely unknown. Objectives of this study were to assess fish survival and reproduction after exposures to 3 forms of fog oil: surface oil films from precipitating smoke, oil-water mixtures produced by physical agitation, and solutions of dissolved fog oil components photo-transformed by ultraviolet from sunlight. Surface oil from single smoke releases produced no mortality in adult fish and egg viability and production did not differ from controls (P >0.05) after 21 days. Repeated smoke exposures of 7 consecutive days had 64% mortality in larvae. Endpoints for 96 hour LC50 tests for oil-water mixtures were 709 mg/L in larvae and 2,150 mg/L in eggs. LC50 values for UV-transformed solutions were 7.4 mg/L in larvae and 18.5 mg/L in eggs. Collectively, fog oils as smoke, mixtures with water, and transformed by UV were found to cause mortality in fish but only at elevated concentrations associated with atypical activities, such as up to 7 days of repeated foggings or potentially a contaminant spill.
Etheostoma, Oil pollution, Fishes
Ryan, T. (2011). <i>Short term effects of military fog oil on the fountain darter (Etheostoma fonticola)</i> (Unpublished thesis). Texas State University-San Marcos, San Marcos, Texas.