Though marine microbes are invisible to the naked eye, there are roughly 10,000,000 in a single drop of seawater. The sheer number of microbes, actively consuming and respiring carbon, enable them to play a role in the marine carbon cycle that far outweighs their individual size. Just like us, heterotrophic marine microbes consume organic carbon and respire a portion of the carbon they've consumed to carbon dioxide. Thus, these tiny microbes can impact the amount of organic carbon that is available for export from the surface ocean, and the production of carbon dioxide in the ocean.
As a PhD student, working with a fantastic undergraduate, Henry Morse, and the Carlson/Passow/Brzezinski labs, I exploited the vastly influential metabolisms of marine microbes to evaluate the impacts of rising carbon dioxide levels on the marine carbon cycle. My research showed that rising carbon dioxide levels in the ocean may lead to increased rates of microbial respiration and consumption of dissolved organic carbon. This work has major implications for the ability of the oceans to continue to absorb human-produced carbon dioxide, and provides yet another line of evidence to suggest that we need to enact effective policies to curb carbon dioxide emissions.
CHECK OUT THE WRITE-UP ABOUT THIS PROJECT IN THE UCSB CURRENT!
Sampling 30 bottle experiments in the South Pacific Subtropical Gyre