Organic matter forensics: combining multiple analytical techniques to understand the role of organic matter in the marine environment

97% of the organic carbon in the ocean is dissolved; that’s 32 times as much carbon than is in all of the living organisms in the ocean, from the tiny phytoplankton to the blue whales. Despite being so big, we know very little about what individual chemicals make up dissolved organic matter, making determining its role in the global carbon cycle challenging. Chemically, dissolved organic matter is very complex, leading different fractions to function in very different ways in the marine ecosystem. For example, some fractions of dissolved organic matter are very good substrates for microbes at the bottom of the food web, and are recycled very quickly in the surface ocean. On the other hand, a very large fraction resists biotic and abiotic degradation and acts as a form of carbon storage throughout the ocean.

Research in our group focuses on using multiple analytical techniques to probe the dissolved organic matter pool and understand the various roles it takes up in the marine carbon cycle. From rivers to the open ocean, we aim to tease apart the chemical qualities that make this pool of organic carbon so enigmatic.