It is important to understand to what extend microbes could play a key role in the degradation of an oil spill in the offshore oligotrophic waters in the assessment area. It could be an optional strategy for remediation of an oil plume to use and potentially enhance the intrinsic bioremediation potential of microorganisms to degrade the oil. Such strategy depends on a number of environmental factors, including presence of microorganism representatives that degrade hydrocarbons or are stimulated by the presence of oil in cold environments, thus a favourable response of indigenous microorganisms to an increased concentration of hydrocarbons and/or dispersant. Another important factor is nutrient limitation. In the case of the Macondo accident in the Gulf of Mexico, microbial respiration within the slick was enhanced by approximately a factor of five and an incubation experiment to determine hydrocarbon degradation rates confirmed that a large fraction of this enhanced respiration was supported by hydrocarbon degradation. Extrapolating these observations to the entire area of the slick suggested that microbes had the potential to degrade a large fraction of the oil as it arrived at the surface from the well. However, a concomitant increase in microbial abundance or biomass was not observed in the slick, suggesting that microbial growth was nutrient limited.
Identifying presence of microorganisms already adapted to degradation of hydrocarbons as well as a possible degradation rate in relation to nutrient availability and application of dispersant in the assessment area would add valuable information regarding the area’s ability of bioremediation, and hence to analysing response strategies.