In a Deep Ocean Trench, Creatures Dine on Sulfur
Eight kilometers down, zero sunlight, crushing pressure, near-freezing water, and a microscopic community running on sulfur in a spot where every clue in the rock says the fuel source should be methane.
Researchers collected sediment from the Atacama Trench, one of the deepest environments in the southeastern Pacific Ocean, and used a technique that reads which genes organisms are actually using. Most of the trench looked like what you'd expect: tiny microbes living off the slow drift of organic matter sinking from the ocean surface, breaking it down in the dark.
One site didn't fit.
Darker sediment. Mats of bacteria that eat sulfur compounds instead of carbon. Clams whose internal bacteria, living inside their gills like built-in power plants, also run on sulfur. And a specific type of crystal in the rock that, at cold seeps, almost always means one thing: methane-eating microbes left it behind.
The methane-eating microbes weren't there.
Instead, the whole community was running on sulfur. Different fuel, different organisms, fully functional ecosystem at the bottom of one of the least-studied ocean trenches on Earth. What formed those crystals without the usual culprits? Still an open question.
This was a first look at the Atacama Trench's microbial life. And on the first look, the biology already disagrees with the geology.
Read the full story at Nature Communications, March 18, 2026
Hot Take: Organisms at 8 kilometers depth, in water that's barely above freezing, running a full sulfur-based economy in a spot geologically wired for something else. This isn't life finding a way, it's life finding its own way, and not consulting the map.
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