Scientists led by Stanford reveal that marine snow, crucial for oceanic carbon sequestration, forms mucus “parachutes” that slow its descent, altering our understanding of climate mitigation and carbon cycles.
New research led by Stanford University reveals a hidden biological process that could transform our understanding of how oceans mitigate climate change. Published in the journal Science, the study unveils mucus “parachutes” produced by microscopic marine organisms that significantly slow their descent, offering new insights into oceanic carbon sequestration.
Marine snow, a blend of dead phytoplankton, bacteria, fecal pellets and other organic particles, plays a critical role in the biological pump, a natural process that absorbs about a third of human-made carbon dioxide from the atmosphere and locks it away in the ocean floor. However, the exact mechanism behind the gradual sinking of these particles remained a mystery until now.
The researchers, using an innovative rotating microscope, discovered that marine snow often creates parachute-like mucus structures. These formations double the duration that particles remain suspended in the ocean’s upper layers, increasing the likelihood of microbial breakdown and significantly impacting the sequestration process.
“We haven’t been looking the right way,” senior author Manu Prakash, an associate professor of bioengineering and of oceans in the Stanford School of Engineering and Stanford Doerr School of Sustainability, said in a news release. “What we found underscores the importance of fundamental scientific observation and the need to study natural processes in their true environments. It’s critical to our ability to mitigate climate change.”
The rotating microscope, developed in Prakash’s lab, simulates vertical travel for marine particles and adjusts conditions to mimic the ocean’s environment. These devices were deployed on research vessels across all the world’s major oceans, from the Arctic to Antarctica, allowing the researchers to capture detailed observations of marine snow in its natural state for the first time.
Lead author Rahul Chajwa, a postdoctoral scholar in Prakash’s lab, emphasized the transformative nature of their findings.
“Theory tells you how a flow around a small particle looks like, but what we saw on the boat was dramatically different. We are at the beginning of understanding these complex dynamics,” he said in the news release.
Chajwa and Prakash highlight the significance of conducting high-resolution microscopy in natural settings, challenging the traditional lab-based approaches that have dominated scientific exploration for the past two centuries. They argue for increased support for research that prioritizes naturalistic observations.
“We cannot even ask the fundamental question of what life does without emulating the environment that it evolved with,” Prakash added. “In biology, stripping it away from its environment has stripped away any of our capacity to ask the right questions.”
The implications of this study are profound, extending beyond academic curiosity to global climate policies. The discovery suggests that previous models of oceanic carbon sequestration might be overestimated, urging adjustments in climate predictions and policy formulations.
The researchers are now refining their models and integrating their findings into larger Earth-scale models. They plan to release an open dataset from their expeditions, aiming to further reveal the factors influencing mucus production in marine snow, such as environmental stressors or the presence of specific bacterial species.
Despite the revelation’s potential challenges to current paradigms, Prakash remains optimistic.
“Every time I observe the world of plankton via our tools, I learn something new,” he added.