Lacie Levy and Ari Paulik, VISIONS’25

More than a mile beneath the ocean’s surface, towering rock chimneys rise from the seafloor as scalding, metal-rich fluids issue into the icy darkness. These dramatic structures—hydrothermal vents—are among the most extreme environments on Earth. The deep sea is commonly imagined as lifeless and barren, locked in perpetual night. Yet around hydrothermal vents, underwater volcanoes fuel a constant supply of gases and metals, providing everything needed to sustain vibrant ecosystems.

To understand how life not only survives but thrives here, we set out to study metabolites—tiny molecules that power processes essential to life. Yet, metabolomic research in the deep sea is rare: hydrothermal vents are difficult to reach, and the salty ocean environment makes chemical measurements challenging.

During the VISIONS’25 Regional Cabled Array expedition to Axial Seamount, the remotely operated vehicle Jason descended nearly a mile below the surface to collect fluid samples adjacent to active hydrothermal vents. Using newly developed analytical technology at the University of Washington, we can now identify metabolites both inside microbial cells and in the surrounding seawater.

This breakthrough will allow us to see more than what individual microbes are doing—it will reveal how they interact. By tracking which metabolites are produced, used, and shared, we can begin to map a hidden “chemical economy,” where microbes exchange molecular resources to survive in one of the most extreme habitats on our planet.