CofC Logo

Comparative Toxicity of Three Shoreline Cleaner Products in Estuarine Organisms: Mesocosm and Laboratory Exposures

Marie DeLorenzo, NOAA

3 February 2017

Oil spills that occur in estuaries, bays, or enclosed harbors have the potential to contaminate docks, bulkheads, ship hulls, and sensitive estuarine habitat. Depending on the situation and location, shoreline cleaners may be applied to oiled surfaces within inshore areas. Decisions as to where and when individual products will be utilized depend on understanding the efficacy, environmental fate, and environmental effects of these compounds.  This study evaluated the efficacy and possible ecotoxicity of three shoreline cleaner products (Accell Clean, PES-51, and Cytosol) using a salt marsh mesocosm test system and laboratory exposures. Ceramic tiles were used to represent oiled seawall. The mesocosms were dosed with oil, followed by shoreline cleaner application to the oiled tiles. Samples were collected at multiple time-points during the 30-day experiment. The Oil+Accell treatment significantly reduced fish, mud snail, and clam survival compared to the control. Both the Oil+Accell and Oil+Cytosol treatments significantly reduced amphipod and polychaete survival. Sublethal effects were observed on clam and marsh grass growth, and dissolved oxygen content was reduced in the shoreline cleaner treatments. While the Oil+Accell treatment had the greatest animal mortality, it had the highest bacterial (heterotrophic and Vibrio) densities. Bacterial densities returned to pre-dose levels after 30d. The Oil+Accell treatment had significantly higher measured hydrocarbons in the water column 24h post-cleaner application than the oil alone treatment, the Oil+PES treatment and the control. The results of this study will help inform management decisions regarding the use of shoreline cleaners in oil-spill response, particularly with regard to estuarine species.