Summary
Human activities in Antarctica pose significant threats to marine ecosystems through accidental fuel spills, primarily as aresult of shipping incidents. This risk is likely to increase due to rises in shipping frequency in the Southern Ocean. Significantcontamination has already occurred in Antarctic waters as a consequence of shipping incidents. For example, the sinking andgrounding of several ships between 1989 and 2007 resulted in the release of large quantities of fuel. The reported environmentaleffects of these incidents have come from a small number of observations only, and little work has been done toinvestigate the toxicological effects of fuels to Antarctic marine biota. Environmental effects of marine fuel spills are partiallydependent on their management and the clean up process in place. Fuel dispersants are not currently used in Antarctica, dueto the lack of information on their effectiveness and their toxicity to Antarctic marine biota. However, dispersants potentiallyoffer an alternative method for spill management, as conventional clean up methods are frequently unsuitable in Antarcticconditions. Experiments focused on IFO 180 residual fuel used in large marine vessels throughout the world, includingAntarctica. A marine fuel spill of IFO 180 is likely to persist long term in the Antarctic environment, representing a significantenvironmental threat and need for management. These experiments investigated the toxicity of different concentrations ofthe water accommodated fractions of IFO 180 fuel and three chemical fuel dispersants, both singularly and in combination,to an Antarctic nemertean and a polychaete species. Preliminary results indicate similar trends for both species, with O. orensanzipolychaetes displaying greater sensitivity. In all cases, toxicity of IFO 180 increased following chemical dispersion. Initialanalyses indicate that the older dispersant product Ardrox was more toxic than the more recently developed dispersantsSlickgone LTSW and Slickgone NS.