Distribution of water soluble components from oil encapsulated in Arctic sea ice: Summary of three field seasons

Field work with oil encapsulated in ice was performed three successive years in van Mijenfjord on Svalbard. The results from these experiments have shown that not only the ice thickness, but also the air temperature prior to an oil spill are important for the distribution of water soluble oil components: A relatively high air temperature leads to a more porous ice, and the major part of the water soluble components (WSC) will leak out quickly and the toxicity in the ice will be low. However, if a spill occurs during extremely cold conditions, the ice is less porous and WSC leak out more slowly. This results in a longer exposure period to toxic WSC for the ice organisms. The results from the three field seasons strongly indicate that the transport of WSC occurs mainly in the brine channels. Thus, the contents of bio-available WSC and their estimated acute toxicity in the brine channels have been calculated. The results indicate that the concentration of WSC in the brine channels is acute toxic to the ice organisms and will most likely cause potentially toxic oil components to enter the Arctic marine food web.