Following the Deepwater Horizon’s spill that BP presented the Gulf of Mexico with beginning in April 2010, It’s tough to envision writing about beneficial natural oil in the same body of water. However, according to researchers phytoplankton thrive above natural oil seeps and phytoplankton are an intricate part of the food chain.
Ok, it’s not really the oil seeps themselves
It’s more of a witches’ brew of nutrients caused by the bubbling and rising above natural oil seeps that brings more nutrients up to the phytoplankton for their consumption. Through evolution, the researchers believe, phytoplankton flock (no, they don’t flock…move/swim, they get there) to these nutrient rich waters.
Phytoplankton are generally eaten by shrimp, which are in turn eaten by larger fish or humans. Addtionally, phytoplankton feed whales and other larger plankton-eating marine life.
Once again, it’s not the oil that is helping the phytoplankton but the nutrients that accompanies the low-concentrations of oil in natural seeps. Phytoplankton populations were found to be nearly double the amount found mere kilometers away where there was no oil seep. The researchers’ findings were published in the latest issue of Nature Geoscience.
“This is the beginning of evidence that some microbes in the Gulf may be preconditioned to survive with oil, at least at lower concentrations,” said Ajit Subramaniam, an oceanographer at Columbia University’s Lamont-Doherty Earth Observatory and co-author of this recent study. “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. This does not mean that exposure to oil at all concentrations for prolonged lengths of time is good for phytoplankton.”
Oil seeps and nutrients studied by tracking chlorophyll fluorescence levels
The researchers compared the levels of chlorophyll florescence levels inside the microbes above known oil seeps and confirmed their findings using satellite imagery and water sampling.
“Satellite radar data have given us a detailed picture of where natural seeps are concentrated across deep seafloor of the Gulf of Mexico,” said co-author Ian MacDonald, an oceanographer and professor at Florida State University. “Building on this, the present, novel results show biological effects near the ocean surface in areas where seeps are most prolific.”
It goes without saying that major oil spills are horrific and affect marine life, coastlines, birds, and the men and women who fish the waters among others, but this finding shows that some marine life will move on if not thrive in low concentration areas of natural oil.