Oil Spill Dispersant Strategies and Biodegradation Efficiency

Aktiviteter i prosjektperioden: 1) Arbeide med og avslutning av biodegraderingsstudier av oljefilmer med ulike tykkelse - Master oppgave som er avsluttet med Master-eksamen 2) Databearbeidelse av biodegraderingsresultater vha. multivariate analyser 3) PhD: Arbeide med biodegraderingseksperimenter for å bestemme hvilke mikrobielle gener som uttrykkes ved nedbryting av dispergert olje

The use of chemical dispersants as an operational tool for marine oil spill treatment will increase the oil attachment areas for the marine microbes and improve oil biodegradation. This may subsequently reduce the impacts of the oil on the marine ecosyste m, although this is debated. The need for information on the fate of chemically dispersed oil is therefore urgent. In this project we will determine the effects on oil biodegradation efficiency caused by dispersant treatment of surface and subsurface oil spills. Oils and dispersants relevant for the Norwegian continental shelf will be used. Various established laboratory systems will be used for dispersant treatment of surface spills, including an oil-on-seawater mesocosm system. Subsurface dispersions wi ll be investigated in a novel system established at SINTEF with an oil dispersion generator and a carousel system for keeping the droplets in suspension. Biodegradation will be determined by GC-MS analyses and related to various oil and dispersant process es and environmental conditions. Selected samples will be analysed by oil fractionation procedures and high-resolution analyses to determine the potential biodegradation of compound groups not normally analysed during biodegradation studies. Microbial eco logy and biochemical processes associated with oil biodegradation will be analysed by molecular microbiology methods. Relevant results will be included in the OSCAR model to improve the biodegradation input data material and to determine if the kinetic mo dels in OSCAR should be modified or not. The final outcome of this project will be knowledge-based information on biodegradation rates and processes to be used in dispersant strategies and to improve the OSCAR model.