Scientists have long studied organisms that thrive around hydrothermal vents. But those native to areas known as cold seeps — where gases like methane and hydrogen sulfite leach from the seafloor at near-freezing temperatures — have been little studied.

A team of researchers discovered a “flourishing” ecosystem of clams, tube worms and other creatures over 30,000 feet below the Pacific Ocean. The discoveries mark the “deepest and the most extensive chemosynthesis-based communities known to exist,

That’s what an international team of scientists did last summer. Led by the Chinese Academy of Sciences, the researchers took a manned submersible to the bottom of deep-sea trenches in an area in the northwest Pacific Ocean,