Oil might not seem like it could be home to, well, anything. We've seen what oil spills can do to ecosystems, and it's hard to imagine that anything would actually live in the black blood of industry. However, researchers have discovered tiny organisms do indeed make their home there, and they are an essential part of the reason that oil degrades over time.

It's important to note that, according to Rainer Meckenstock from the Helmholtz Zentrum München (HMGU), the microorganisms are not living in the oil itself, but rather in tiny water droplets that the oil naturally encapsulates.

"Inside them we found complex microbial communities, which play an active part in oil degradation," he said in a recent release.

A study detailing these complex microbial integrations with oil are detailed in the journal Science.

Prior to Meskenstock's study, it was assumed that microbial oil degradation only occurred when water non-native to the oil was introduced, beginning a long process that eventually breaks down the "black gold." However, analysis led by Meckenstock and conducted by international colleagues from the Technical University of Berlin, Washington State University, and the University of West Indies, determined that this process also naturally occurs within the oil itself. This effectively puts an expiration date - albeit a long one - on untapped oil.

Meckenstock explained that oil degradation slowly changes its composition and eventually leads to the formation of viscous bitumen, or "oil sands." These are the same black sands that are a huge part of tar sand composition - the same bitumen material that helps make asphalt.

This helps explain why more than two trillion barrels of the world's oil is in the form of tar sands, which cannot be pumped and must be mined, according to the US Department of the Interior's Bureau of Land Management.

"Our data thus supplies important information about oil quality and is therefore essential for the industry that surrounds what is still the most important energy source worldwide," Meckenstock explained.

This isn't all bad news. The authors of the study say that better understanding these microorganism communities will help them figure out how to promote faster cleanups of oil spills and groundwater pollution.

However, more research must first be conducted.