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buchanA better understanding of how carbon cycles through the ocean could advance our knowledge of climate change, according to a UT researcher.

From beach shallows to the ocean depths, vast numbers of microbes work together to transform and store atmospheric carbon in the world’s oceans, compounds collectively referred to as dissolved organic carbon (DOC). But studying the connections between those ocean-borne compounds and microbes has been impractical because of their huge number and complexity—until now.

UT researcher Alison Buchan, along with a team of US and international scientists, has identified technological developments that are providing scientists with the analytical tools needed to understand these molecular-level relationships.

Their perspective article appeared March 7 in the Proceedings of the National Academy of Sciences. It focuses on dissolved organic matter in the world’s oceans as a central carbon reservoir in the current and future global carbon cycle.

Climate change is largely attributed to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels.

“The paper is intended to serve as a roadmap for future research in the area of ocean carbon cycling,” said Buchan, the Carolyn W. Fite Associate Professor of Microbiology. “This topic is recognized as a high priority research area in earth, ocean, and microbial sciences.”

The world’s oceans play a critical role in the cycling of carbon, Buchan said. Collectively, organisms that transform energy from the sun into chemical energy convert carbon dioxide to organic carbon, much of which resides in the dissolved organic carbon reservoir and is a food source for the large numbers of microbes that live in seawater. The microbes rapidly transform some of the DOC back to carbon dioxide, but a lot of it is stashed in the ocean.

“We don’t know why so much of this material is not readily eaten by microbes. We don’t even really know what this complex mixture of dissolved organic carbon looks like from a chemical standpoint nor which microbes eat select components,” Buchan said. “While there is still a lot we don’t know, we are making important advances that are helping us to better connect the consumer microbes with dissolved organic carbon transformations.”

The paper provides the scientific community with information that includes the current state of knowledge in the area of ocean dissolved organic carbon-microbe interactions and transformations, and stresses that the most significant advances in the understanding of this relationship come from studies that pull together scientists from diverse fields.

“This paper is a call to arms for a broad collection of scientists and those who make decisions about funding for science,” Buchan said. “It helps advance the field by not just highlighting the gaps in our knowledge but suggesting concrete steps forward that are achievable, given emerging technologies.”

Technology has advanced so much in recent years that scientists now have the tools, such as advanced mass spectrometry, that allow them to better tease apart the chemical structure of components of dissolved organic carbon and sequence the genes of all the microbes in seawater to better understand what they are capable of. They also benefit from better computational algorithms and computing power that allow them to examine the immense data sets gleaned from application of these technologies.

The perspective article, “Deciphering Ocean Carbon in a Changing World,” was born out of discussions at a 2014 workshop supported by the Gordon and Betty Moore Foundation and Microsoft Research Corporation.

Co-authors on the paper include researchers from the University of Georgia; the University of California, San Diego; Oregon State University; Columbia University; the Pacific Northwest National Laboratory in Richland, Washington; the University of Washington; the University of Oldenburg in Germany; Sorbonne Universités, and the University of Chicago.


Lola Alapo (865-974-3993,

Alison Buchan (865-974-5234,