Biogeochemist Karen Lloyd joins USC faculty as Wrigley Chair in Environmental Studies

By Kathryn Royster

Karen Lloyd, a renowned biogeochemist known for her work on microbes that live deep beneath the Earth’s surface, has joined the USC faculty as the Wrigley Chair in Environmental Studies and professor of Earth sciences.

“I am thrilled to welcome Karen to USC as part of the Wrigley Institute community and the university’s world-class team of environmental and sustainability scholars,” says Wrigley Institute Director Joe Árvai. “She is the rare researcher who does groundbreaking work that addresses real-world needs while also communicating about it in a way that is both entertaining and insightful. The Wrigley Institute, and our extended community, are lucky to have her.”

Lloyd’s research focuses on microbes that live in environments such as the bottom of the ocean, hot springs, or under Arctic permafrost. Some of these microbes have extremely slow metabolisms–so slow that they can go thousands of years without reproducing, experiencing molecular turnover, or eating. Lloyd seeks to understand why the organisms are in this state, whether their slow metabolisms are an evolutionary advantage, what kinds of conditions might cause them to “wake up,” and how their presence and activities might intersect with climate change.

To uncover the answers to these questions, Lloyd focuses heavily on a field-first approach to research. This approach comes partly by necessity: the microbes she studies reproduce so slowly that she could literally spend the rest of her life waiting for a culture to grow in a Petri dish. But she also prefers fieldwork for its true-to-life conditions.

“You can do all the theoretical lab work you want, but when you’re in the wild with so many factors affecting the organism, it may perform differently. That’s why I always measure things in the wild as much as possible,” Lloyd says.

Her preference for getting out into the field runs deep. Growing up on the rural North Carolina coast, Lloyd spent many hours exploring the environment around her home. She was particularly fond of the ocean–so fond of it, in fact, that at age 13, she literally knocked on the door of the Duke University Marine Lab and asked if she could assist the researchers.

“I went to college with the aim of majoring in biology and just got sucked up by chemistry,” Lloyd says. “It was like solving puzzles. But I couldn’t imagine spending the rest of my life only in a lab, so I decided to study oceanography as well.”

Now that Lloyd has arrived in Los Angeles, the destination seems almost inevitable. She first encountered the Wrigley Institute and USC as a Ph.D. student, when she attended a summer course taught by faculty affiliate Will Berelson at the Wrigley Marine Science Center. That experience touched off a long-term connection with USC, even as she went on to a postdoctoral fellowship in Denmark and joined the faculty at the University of Tennessee Knoxville.

Over the years, she collaborated numerous times with the late Jan Amend, who was a microbiologist and USC Dornsife divisional dean of life sciences. Many of her other co-researchers have been USC graduate students or alumni. She says that USC’s unique strengths in marine microbiology, geobiology, Earth sciences, and engineering were a strong draw for her. Add the wealth of local opportunities for collaboration–with JPL, Caltech, UCLA, Cal State, and the Natural History Museum of L.A., to name a few–and it was an easy “yes” to make the cross-country move from Knoxville to L.A.

Lloyd is excited to be in a coastal city once again, and to have the world’s largest ocean (or, from her perspective, living lab) right on her doorstep. One of her first projects in her new role: studying methane-eating microbes in the San Pedro Channel between L.A. and Catalina Island.

Methane is a planet-warming gas that is up to 20 times more potent than carbon dioxide. It occurs naturally as plants and animals decay, but it’s also created by human activity, especially the use of agricultural fertilizers. Methane in the San Pedro Channel comes from human and natural sources and is both produced in the ocean and carried to it by runoff.

The gas is not naturally very soluble in water, so it tends to escape quickly into the atmosphere–unless methane-eating microbes get to it first. Through their natural movements, or when they die, these microbes sequester the methane by taking it to deeper waters. Deep ocean water cycles to the surface slowly, so methane sequestered this way may stay out of the atmosphere for tens, hundreds, or even thousands of years.

We don’t currently know how much methane is in the San Pedro Channel, how much of it is escaping to the surface, or whether the local microbes are keeping up with the supply. Those are the questions Lloyd hopes to answer, aided by two Wrigley Institute postdoctoral researchers and the institute’s San Pedro Ocean Time-series. 

Lloyd’s results can help us understand the effects of runoff from large urban areas like Los Angeles, how quickly climate change may intensify as methane enters the atmosphere, and what we can do to protect ourselves and our planet. She also hopes her work will help people appreciate just how important these hidden, mysterious microbes are to our lives.

“This kind of activity is happening not just in the channel but in groundwater, in the Arctic, in hot springs, and other places,” Lloyd says. “A huge biosphere lies under our feet all over the world, and we’re just beginning to figure out what they’re doing and how they can help us”

Karen Lloyd’s research on methane in the San Pedro Channel is supported in part by the Wrigley Institute’s Ballmer Group-funded Climate and Carbon Management Initiative.

Learn more about the Climate and Carbon Management Initiative >>

Learn more about Wrigley Institute faculty research >>

Read Lloyd’s paper on slow-growing microbes >>

Watch Lloyd’s TED Talk on deep-ocean microbes >>