Samenvatting

With the increase of offshore activities in the Arctic, the question arises if currently existing oil spill response plans involve effective methods for removing oil slicks in Arctic conditions. The dispersant Corexit9500 is commonly applied as response agent to disperse oil slicks. It has been applied at many oil spill accidents. EcoTech Oil Foam is a newly developed absorbent. Little is known concerning the toxicity of EcoTech and Corexit9500 in low water temperature (4°C). Aim of the research is to provide knowledge on the feasibility of oil response agents in the Arctic. Research question of this project: Can Corexit9500 and EcoTech Oil Foam be recommended as response agents for combating offshore oil spills in low water temperatures? Plunge tests were conducted to test the dispersion behaviour of Helder oil and Mississippi Canyon Block 252 oil with and without using Corexit9500 at different water temperatures. Acute toxicity tests have been conducted by exposing Corophium volutator to Mississippi Canyon Block 252 oil. Growth inhibition tests have been conducted on the phytoplankton species Phaeodactylum tricornutum. Tests were based on the Water Accommodated Fracture preparation. At 4°C, oil with and without Corexit9500 are less dispersed and produce larger droplets compared to dispersion at 18°C. Oil slicks treated with Corexit9500 proved more toxic compared to oil treated with EcoTech or solely oil at 18°C. At 4°C Corexit9500 proved less toxic compared to untreated oil, however it is questionable if these data are correct. EcoTech proved difficult to apply in tests, it was not possible to conduct 4°C experiments. Corexit9500 proved less toxic at 4°C compared to 18°C (0.3949 vs 0.02104 ml oil/L). The growth inhibition test resulted in no significant difference between treatments. It is assumed that the experimental set up was inefficient for this type of research. For future research, it is recommended to conduct experiments with a variation of test organisms. And to create a toxic concentration based on a dilution range of one water accommodated fracture volume.