Off-shore oil exploration and production is moving towards Arctic regions. A strict regulation according to a precautionary principle has been invoked for the oil and gas industry. There is a strong official requirement to avoid long term environmental impacts or effects that may be in conflict with the fisheries. The knowledge about the environmental impact of such activities in these regions has to be expanded. Since regular discharges will practically be prohibited, the possible environmental spill scenarios on the marine environment from the oil industry are mainly focused on accidental spills. These may include large as well as small repeated discharges related to oil spill events in the course of production, processing or transport and to subsequent re-releases of temporarily stored oil, e.g. trapped in sea ice. At present it is difficult to express the probability for the occurrence of such events or its associated environmental risk, so a scenario based approach is used to identify relevant research targets. The selected scenario is related to oil drift into ice margin, and the project work is focusing on potentially long term effects on ice margin community of trapped oil. This may occur as oil trapped underneath the sea ice or as frozen within the sea ice. Potential long term effects are determined by results of experiments. From the results it will be attempted to express their influence on expected restitution time. The data on uptake and effects will be relevant for validation of hazard and risk estimates as well as a support for environmentally related decision making at accidents as well as industrial operations in Arctic waters. The work will be divided into three work packages, high-lighting different aspects of potential effects on the ice amphipod Gammarus wilkitzkii. WP1: Uptake and effects of water dissolved and food-bound hydrocarbons. WP2: Effects on reproduction cycle and population with links to short term/medium term effects. WP3: Long term effects by repeated exposures of released oil. The presence of UV-light will be included as an experimental factor due to the combination of large amounts of sunlight in the Arctic summer and its influence on oil (PAH) toxicity. Two different doses of oil will be tested in order to assess the difference in effects in relation to oil load (exposure concentrations). The project will be carried out in close co-operation with a doctorate study related to UV effects on Arctic amphipods funded by the German Research Council.