Understanding the global ocean microbiome

The community of microorganisms in the world's oceans turn out to be the most important control mechanisms of how the Earth functions. Understanding their function and behavior will leverage our grasp on how the Earth will adjust to broad environmental changes, says Mary Ann Moran in a review article in the journal Science:

The ocean microbiome covers the majority of the Earth's surface, extending an average of more than 2 miles deep to the sea floor. Made up of an extraordinary diversity of microorganisms, the ocean microbiome was one of the first microbiomes to be studied. As its distribution and makeup become better understood, questions about its functional capabilities under stress have grown.

"Marine microbes make up a vast biological network," said Moran, a Distinguished Research Professor in the UGA Franklin College of Arts and Sciences. "Microbes are responsible for virtually all the photosynthesis that occurs in the ocean, as well as the cycling of carbon, nitrogen, phosphorus and other nutrients and trace elements. They literally run the oceans."

The article recounts the history of investigations into the microbial communities that populate the ocean—and, critically, help supply a large proportion of the oxygen in the atmosphere.

"A consistent link is emerging between ocean temperature and both the composition and productivity of microbes inhabiting surface seawater," she wrote in Science. "Earth's changing climate will affect characteristics of the ocean microbiome."

Investigations of the ocean microbiome already have a rich history, which has presented breakthroughs and far-reaching epiphanies. But just like our understanding of the role of microorganisms in the human body, the mysteries of the ocean microbiome continue to reveal implications and connections that permit a deeper understanding of the system, its capacities and how it works in concert to achieve health and balance. Hopefully this expanded knowledge begin to affect human behavior and the consideration we give to our interactions with these broad, overarching systems. By all accounts and especially Dr. Moran's in this important publication, it's an exciting time to be a marine scientist.

Image: Mary Ann Moran off the coast of Sapelo Island. (Credit: Peter Frey/UGA)