Microbes can attack oil in Arctic seas

Alan Bailey

for Petroleum News

Researchers in the University of Calgary, Canada, have conducted experiments that demonstrate that microbes in the seafloor in Arctic conditions decompose crude oil. The microbes in question exist in the benthic zone, close to the seafloor. Given that some portion of spilled crude oil sinks, the researchers suggest that these microbial communities are important in considering the fate of oil spilled in the Arctic offshore. The Canadian researchers are particularly interested in conditions in the Labrador Sea, where there is increased ship traffic and potential oil production.

“Understanding how cold-adapted microbiomes catalyze hydrocarbon degradation at low in situ temperature is crucial in the Labrador Sea, which remains relatively cold throughout the year,” the researchers say.

To evaluate the impact of microbes on oil the researchers mixed diesel or crude oil with sediments from the Labrador Sea seafloor and artificial seawater. While monitoring the response of the microbes to the oil over several weeks, the researchers kept the mixtures at low temperatures corresponding to conditions at the seafloor. They found that several types of microbes degraded the oil. And artificial stimulation of the microbe community also stimulated the oil degradation process.

A few years ago a research team in the University of Alaska Fairbanks conducted some similar experiments, incubating North Slope oil in bottled seawater at temperatures around freezing. The researchers found that the biodegradation of the oil in the cold water took place almost as rapidly as it does in water at temperatures found in more temperate regions. However, the oil does tend to evaporate more quickly in warmer temperatures.

- ALAN BAILEY