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History has seen several major oil spills ravage the delicate marine ecosystems across the globe, and especially around the Alaskan region (remember Exxon Valdez!). When oil spills occur, they form an unsightly black layer on the surface of water bodies that has long-term implications for the environment. Aside from cutting off the oxygen supply to the marine biota that lives beneath the water’s surface, it also traps birds that dive in to catch food.
But, as they say, nature always finds a way to heal itself—bacterias capable of ‘eating’ oil! These microorganisms occur in warmer waters with a temperature of around 30°C. However, a new study revealed that there are such bacteria even in fragile ecosystems like the northern polar region and stimulating them with nutrients can help clean up the oils from the seas much faster.
The researchers arrived at this conclusion by identifying marine bacteria in the frigid waters of the Canadian Arctic (having temperatures of about 4°C) that were capable of biodegrading oil and diesel fuel.
The coastal areas of the Labrador Sea in Canada have been seeing increasingly more industrial activity and transportation of diesel and crude oil. By 2030, the government of Newfoundland and Labrador have planned to drill “over 100 additional exploratory wells” in basins that would generate “over 650,000 barrels of oil per day.” These developments considerably increase the probability of future oil spills.
To mitigate the environmental risks this will lead to, scientists at the University of Calgary, Canada, conducted a study to find key players in oil clean up in the cold seas of Labrador.
“As climate change extends ice-free periods and increasing industrial activity takes place in the Arctic, it is important to understand the ways in which the Arctic marine microbiome will respond if there is an oil or fuel spill,” said Dr Hubert, a co-author of the research article. He felt that this was important because “this region remains vast and remote such that oil spill emergency response would be complicated and slow.”
Sean Murphy—the lead author of the study and a native of Newfoundland, had collected bacterial samples from the Labrador Sea near the Canadian East Coast back in 2015. Genomic sequencing revealed that the bacterial lineages possessed the unique ability to bioremediate hydrocarbons. The bacterial families identified—Paraperlucidibaca, Cycloclasticus, and Zhongshania—had never been found in the cold waters of the Labrador Sea.
To test the bacteria’s ability to eat the oil, the scientists simulated an oil spill within bottles using mud collected from the top layer of the sea bed and artificial seawater. They then added diesel or crude oil and other nutritional supplements to support the bacteria and facilitate faster breakdown. Researchers maintained a temperature of 4°C to replicate the conditions of the Labrador Sea.
Murphy emphasised that the addition of nutrients like nitrogen and phosphorus could act as fertilisers and potentially speed up the entire process. “The study also confirmed that providing nutrients can enhance hydrocarbon biodegradation under these low-temperature conditions,” said Dr Hubert.
According to Dr Hubert, the Labrador coast, where the study took place, is vital for Indigenous peoples who rely on the ocean for subsistence, and bioremediation studies have been scarce in these areas.