Deep beneath the surface of the worlds’ oceans, a massive blizzard is swirling in slow motion. This storm of “marine snow” consists of tiny particles of organic matter; carbon-rich fragments of dead tissue and feces from plankton, fish, and other animals. Its significance goes far beyond just being waste material: as these particles sink down from the sunlit surface waters, they become an essential source of food for other marine creatures—and in the process, play a crucial role in the regulation of global climate. Their gradual descent through the ocean serves as a giant conveyor belt for carbon, moving it from the surface to the deep sea where it can remain sequestered for hundreds to thousands of years.
Scientists have known about the importance of marine snow for decades, but actually quantifying that snow—determining its source, its sinking speed, and its carbon content to figure out its ecological and climate impact—has remained an elusive challenge.
A new device designed at WHOI, called the Twilight Zone Explorer (TZEx), may provide a solution. It’s designed to hover in the twilight zone, a region of dark water roughly 200-1000 meters down, and as it drifts through that realm, it’s able to capture sinking particles, measure their speed using onboard cameras, and preserve their contents for study at the surface—something few other devices have been able to do.
“TZEx will let us tackle some really basic scientific questions about marine snow that have yet to be answered. Namely, how much falls in a given location? How do those levels change over time? What role do certain animals play in creating it or consuming it?” says Ken Buesseler, a marine radiochemist who works with WHOI’s Ocean Twilight Zone project, or OTZ.