The Ocean Carbon Cycle

The oceans play a major role in the global carbon cycle and in regulating climate. The Komada Lab targets one unsolved mystery of the ocean carbon cycle: the occurrence of marine dissolved organic matter (DOM). DOM is an energy source for marine microbes, yet part of the DOM pool is not consumed by microbes and persists in the oceans for centuries to millennia, or even longer. To understand the occurrence of long-lived DOM molecules, their project focuses on one of the major sources of DOM to the ocean water column: the seafloor. They aim to identify types of DOM molecules that are not readily consumed by sediment microbes, and to gain understanding about why and how these DOM molecules remain ‘uneaten’. This work is important, because the amount of carbon stored in marine DOM is comparable in size to carbon in the atmosphere today, but we have limited understanding about how carbon cycles through the marine DOM pool. By shedding light on the molecular composition and the transformation pathways of marine DOM, we expect to contribute to a more robust understanding of the role the oceans play in the global carbon cycle.