Effects of outboard motor emissions on early development of the killifish Oryzias latipes

Two stroke outboard engines produce large quantities of combustion emission s per liter of fuel consumed. To determine the environmental risk of outboa rd motor emissions (OME) to the early life stages of fish, we exposed killi fish (Medaka), Oryzias latipes, embryos to water contaminated with OME. Tim e for larval development, incidence of larval abnormalities, and larval mor tality all increased, and length of hatched larvae decreased, with exposure to increasing concentrations of OME-contaminated water. Chemical analysis using solid phase extraction, followed by gas chromatography, indicated hig h concentrations of polycyclic aromatic hydrocarbons in the OME water. Appl ication of these results to hypothetical lakes suggests significant risks t o fish development in the case of high OME input rates to small lakes.