Sam-geun Lee, Hak-gyoon Kim, Eun-seob Cho and Chang kyu Lee, Harmful Algal Blooms Research Division, National Fisheries Research and Development Institute, Busan 619-900, Korea

Abstract

The bioassay and toxicity tests were conducted to investigate the effects of various concentrations of Kuwait oil, Arab oil, Bunker-C, diesel oil, kerosene, oil spill dispersants and mixtures of oil and dispersant on growth of the harmful alga Cochlodinium polykrikoides. Growth of C. polykrikoides treated with higher concentrations (³50 ppm) was found to decline markedly 4-10 days after the addition of oils used in this study compared with the control, whereas £ 1 ppm had no significant effect on growth. Similarly, growth was inhibited when the cells were exposed to higher concentrations in dispersants (³50 ppm), but they exhibited similar growth across the range of less than 1 ppm. In 10 days after the cells were exposed to higher concentrations mixtures of oil and dispersant (³50 ppm), C. polykrikoides was almost died regardless of types of oils and dispersants. However, lower concentrations (£1 ppm) did not play a role in critical toxicity concentration for supressing the growth of C. polykrikoides. These results suggest that higher concentrations of oils, dispersants and even mixtures make a serious impact of C. polykrikoides, whereas the cells were not associated with toxicity, with lower concentrations.