According to a study recently published in Nature Geoscience, natural underwater oil seeps might actually aid marine life—tiny, photosynthetic, microbial life, to be specific.
Researchers from Columbia University's Earth Institute examining phytoplankton in the Gulf of Mexico were surprised to find the microbes concentrated around the natural oil that swells up from the ocean floor. That's not because the oil itself is good for the microbes, but because when the oil bubbles rise to the surface they bring nutrients with them. These are good for the phytoplankton. The researchers explain in a statement:
The oil itself does not appear to help the phytoplankton, but the low concentration of oil found above natural seeps isn’t killing them, and turbulence from the rising oil and gas bubbles is bringing up deep-water nutrients that phytoplankton need to grow… The result: phytoplankton concentrations above oil seeps are as much as twice the size of populations only a few kilometers away.
Study co-author Ajit Subramaniam added, "This is the beginning of evidence that some microbes in the Gulf may be preconditioned to survive with oil, at least at lower concentrations… In this case, we clearly see these phytoplankton are not negatively affected at low concentrations of oil, and there is an accompanying process that helps them thrive." However, Subramanaim explained, "This does not mean that exposure to oil at all concentrations for prolonged lengths of time is good for phytoplankton.”
To reach this conclusion, the researchers used satellite images, water samplings, and something called chlorophyll fluorescence, a way to measure photosynthetic energy.
The scientists stress that there are sharp differences between natural oil swells and oil from spills—like, for example, the disastrous 2010 Deepwater Horizon spill. Natural oil seeps last just a few days and affect up to 100 square kilometers of ocean water, while the Deepwater spill lasted months and affected about 11,200 square kilometers. And the affects of the Deepwater spill have been far from positive: As the National Wildlife Federation reports, the spill has led to sick dolphins, stranded sea turtles, and more. So don't get too excited, BP.
Danielle Wiener-Bronner is a news reporter.