
Marine snow is organic debris and fecal pellets that clump together to form millimeter-long flakes as they fall through the water column.
Photo Credit: ©Woods Hole Oceanographic Institution
Scientific Frontline: Extended "At a Glance" Summary: Marine Snow and the Biological Carbon Pump
The Core Concept: Marine snow is the continuous drift of organic debris—such as dead plankton and fecal pellets—from the ocean's surface down to the deep sea, serving as a primary mechanism for long-term carbon sequestration.
Key Distinction/Mechanism: Rather than sinking passively via gravity, these particles host microbial hitchhikers that actively dissolve calcium carbonate, the mineral acting as the particles' ballast. This localized chemical reshaping makes the particles lighter, causing them to break down at shallower depths and ultimately slowing the efficiency of the ocean's carbon sink.
Origin/History: The discovery of this microbial influence was published on March 11, 2026, in the Proceedings of the National Academy of Sciences by researchers from the Woods Hole Oceanographic Institution (WHOI), MIT, and Rutgers University. It solves a decades-old puzzle regarding why calcium carbonate dissolves in relatively shallow waters despite seemingly stable chemical conditions.










.jpg)


