Credit: Carlos Barria/Reuters/Corbis

Water droplets suspended in the world's largest tar 'lake' are teeming with diverse ecosystems of bacteria and methane-producing microorganisms, despite the inhospitable living conditions.

Droplets just a few microlitres in volume that were isolated from Pitch Lake (pictured), a huge tar pit on the island of Trinidad, contain a menagerie of bacteria and archaea, report Rainer Meckenstock at the Helmholtz Zentrum in Munich, Germany, and his colleagues. They used DNA sequencing to reveal that multiple species work together to break down the oil surrounding the water droplets, which are thought to originate deep underground.

These microhabitats could be an unrecognized factor in the biodegradation of large volumes of oil, the authors suggest.

Science 345, 673–676 (2014) Footnote 1