IMPACT OF OIL CONTAMINATION AND BIOREMEDIATION TREATMENTSON THE COMPOSITION AND DEGRADATION EFFICIENCYOF POLAR BACTERIAL SEA-ICE COMMUNITIES

The threat of a hydrocarbon contamination in the sea-ice covered areas is growing rapidly dueto increasing human activities in the polar regions, which require petroleum as energy source,and due to a fast growing interest in exploiting the estimated one fourth of the world?s oilreservoirs of the Arctic Ocean.This dissertation assessed the influence of crude oil contamination on sea-ice microbialcommunities (SIMCO) in the Arctic and the Southern Ocean. Field and laboratory experiments were conducted with indigenous sea-ice bacterial communities, while testing three fertilizers, Inipol, fish meal, and soluble inorganic nutrients, for the stimulation of hydrocarbon biodegradation. To test whether bioaugmentation can further enhance oil biodegradation processes, oil degrading bacteria were enriched and reinoculated in oil contaminated sea-ice. The response of the bacterial sea-ice communities was assessed by the molecular methods DGGE andFISH. Hydrocarbon degradation efficiency was determined with oil fingerprints obtained by GC-FID and radio tracer experiments of single hydrocarbon substances