Marine snow viscosity regulates microbial degradation and the ocean carbon sink.

Marine snow aggregates with higher viscosity take longer to degrade, sink farther, and enhance carbon sequestration in the ocean.

• Why it matters: Understanding the physical constraints on bacterial colonization and degradation of marine snow is crucial for predicting the ocean's role in global carbon cycling and sequestration.
• What they did: Using molecular rotors to measure nanoscale viscosity, the study analyzed natural aggregates and quantified how viscosity influences bacterial infiltration and degradation rates.
• The result: Findings suggest that aggregate viscosity acts as a microscale physical barrier, affecting degradation time and sinking distance, thereby impacting the efficiency of the ocean carbon sink.