PHOTOTOXICITY OF INDIVIDUAL POLYCYCLIC AROMATIC-HYDROCARBONS AND PETROLEUM TO MARINE INVERTEBRATE LARVAE AND JUVENILES

Phototoxicity resulting from photoactivated polycyclic aromatic hydroc arbons (PAHs) has been reported in the literature for a variety of fre shwater organisms. The magnitude of increase in PAH toxicity often exc eeds a factor of 100. In the marine environment phototoxicity to marin e organisms has not been reported for individual or complex mixtures o f PAHs. In this study, larvae and juveniles of the bivalve, Mulinia la teralis, and juveniles of the mysid shrimp, Mysidopsis bahia, were exp osed to individual known phototoxic PAHs (anthracene, fluoranthene, py rene), as well as the water-accommodated fractions of several petroleu m products (Fuel Oil #2, Arabian Light Crude, Prudhoe Bay Crude, Fuel Oil #6) containing PAHs. Phototoxicity of individual PAHs was 12 to >5 0,000 times that of conventional toxicity. Three of the petroleum prod ucts demonstrated phototoxicity while the lightest product, Fuel Oil # 2, was not phototoxic at the concentrations tested. The phototoxicity of petroleum products appears to be dependent on the composition and c oncentrations of phototoxic PAHs present: lighter oils have fewer mult iple aromatic ring, phototoxic compounds while heavier oils have highe r levels of these types of molecules. This study shows that phototoxic ity can occur in marine waters to marine species. Further, the occurre nce of oil in marine waters presents the additional risk of phototoxic ity not routinely assessed for during oil spills.