Acute mortality of anthracene-contaminated fish exposed to sunlight

Abstract Acute mortality of bluegill sunfish ( Lepomis macrochirus ) dosed with anthracene at 12.7 μg/l and exposed to natural sunlight conditions was observed during a study of anthracene fate in outdoor channel microcosms. No mortality was observed under control conditions (natural sunlight and no anthracene). Fish survived when held in the shade downstream of sunlit contaminated water, arguing against mortality due to toxic anthracene photoproducts in the water. Fish held 48 h in anthracene contaminated water (≈ 12 μg/l), in a shaded channel, died when placed in clean water and exposed to sunlight. After 144 h depuration in darkness, fish anthracene concentrations had decreased to pre-exposure concentrations and no mortality was observed when fish were subsequently exposed to sunlight. This observed photo-induced toxic response in anthracene contaminated fish may represent a significant environmental hazard of polycyclic aromatic hydrocarbons in aquatic environments.