When oil is released into the sea, it is not always the result of an oil spill. There are naturally occurring hydrocarbon seeps on the ocean floor where microorganisms use the escaping oil as a source for energy and food. In a laboratory experiment, researchers from MARUM—Center for Marine Environmental Sciences at the University of Bremen and from the Institute for Chemistry and Biology of the Marine Environment (ICBM) at the University of Oldenburg have discovered what happens to the naturally escaping water-soluble part of the oil. While a portion of it serves as a source of energy and food for microorganisms, there are also non-biologically degradable components that are released and persist in the oceans for thousands of years. The team has published the results of their laboratory experiment in the international journal Environmental Science & Technology.