Just as above-ground landscapes from the tropical rain forests to the alpine tundra support a variety of life forms, landforms beneath the sea provide an array of rich marine ecosystems. And scientists are only just beginning to uncover the diversity of life in the deep ocean.
“Once we started looking at the genetics of deep-sea fishes, we found that they’re far more diverse than people once thought,” says John Sparks, curator in the Department of Ichthyology and curator of the current special exhibition Unseen Oceans. “We also discovered that bioluminescence has evolved many more times than we ever imagined in marine fishes.”
Life can flourish in the most extreme environments. In July 2011, an expedition by the Scripps Institution of Oceanography in La Jolla, California, dropped untethered digital video cameras developed by the National Geographic Society into the Mariana Trench in the Pacific Ocean, the deepest-known spot on Earth. (By contrast, if Mount Everest were located in the trench, there would still be around 6,864 feet of water between its peak and the surface!)
Near the bottom, at about 6.6 miles, the cameras captured images of 4-inch ameboid animals called xenophyophores—among the largest-known single-celled organisms—as well as deep-sea jellyfish. And during the 2015 Galápagos expedition that refined deep sea depth reading, a new species of catshark was discovered.
Meanwhile, the Hudson Canyon in the Atlantic Ocean, carved by the ancient Hudson River tens of thousands of years ago, is a biodiversity hotspot that supports numerous fishes, including bottom-dwelling tilefish, deep-sea corals and sponges, and microbes that aggressively oxidize methane seeping up from the seafloor.
If some of these so-called extremophiles can survive in places previously thought uninhabitable, perhaps there are life forms waiting to be discovered somewhere even more remote and seemingly inhospitable—like in the frozen oceans of Jupiter's moon, Europa.
Find out more about deep-sea marine life in the special exhibition Unseen Oceans, which is free for Members.
A version of this story originally appeared in the Spring 2018 issue of Rotunda, the Member magazine.