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Kendra Daly studies key Antarctic food source

AAAS Fellow Kendra Daly is a professor of biological oceanography at the University of South Florida. She spends a lot of her days researching zooplankton ecology. (Photo: Courtesy of USF)

Researching zooplankton ecology in the most extreme ocean environments on the planet has taught AAAS Fellow Kendra Daly a thing or two about field work. She has spent so many days at sea that it adds up to nine years, almost a quarter of her career as a biological oceanographer. And no matter the location, one thing holds true—field work doesn't always go as planned.

"It doesn't matter how well you plan a science project," said Daly, a professor of biological oceanography at the University of South Florida. "You get out there and the weather is bad, all the krill disappear, the whales don't show up that year. It's not always bad. Sometimes things happen and you think 'Oh wow! This is exciting,' and you go in a different direction. Serendipity plays a role in science."

This is especially true in the Southern Ocean. Any kind of equipment in that cold of an environment is going to have issues. Metal breaks. Sensors stop working. Storms delay data collection. But the physical, mental and scientific challenges keep Daly coming back to the waters around Antarctica. 

"Polar environments are still one of the great unknowns," said Daly, who has made at least 20 trips to the region. "They are so mysterious and breathtakingly beautiful."

Collecting and analyzing samples from an ice-strengthened vessel, Daly and her team study krill, the small shrimp that are a key food source for many species in the region, including penguins, seals and whales. Many nations fish the krill for animal feed and other products, making it even more important to understand the resource.

Since 1981, Daly has helped to develop an improved understanding of the Antarctic krill life cycle. She found that they evolved to make use of sea ice, which thaws and freezes seasonally. Their reproductive cycle is timed so that krill reach a vulnerable larval stage during the winter when there is more ice with algae growing underneath it. The algae provides food and the sea ice provides hiding places for young. This is a key factor as other researchers try to understand how Antarctic sea ice cover changes affect the krill. If their population takes a hit, it could have an outsized impact on the creatures that depend on them for food.

"We don't understand the strengths of those links yet," Daly said.

Daly was born in Southern California and spent her youth in Connecticut on the Long Island Sound. "I was always a budding biologist," she said. "Even before kindergarten, I was dragging home mussels. My poor mother, we always had all these dead things in Campbell's soup cans. I wanted to watch them."

When she raced sailboats as a teen, she often wondered what was happening beneath the surface. When she found out it was possible to get paid to study the ocean, she knew that was the life for her.

"I love being on the ocean; I love the adventure and the mystery," she said.

Daly attended the University of Washington, which offered a bachelor degree in oceanography. Upon graduation, she worked for about 18 years as an oceanographer for the university, running much of the field work for a plankton lab.

She reached a significant turning point in her career when the lab's principal investigator, who had served as her mentor, passed away. She decided to go back to school, earning her Ph.D. in 1995, which opened up the world of academia, as well as other opportunities. She became a program manager for the biological oceanography program at the National Science Foundation from 1997 to 2001, and served as the director of the Ocean Observatories Initiative from 2006 to 2007.

Since 2010, one of her key areas of research has been the Deepwater Horizon oil spill in the Gulf of Mexico. Daly has focused on the role of marine snow in sinking oil. She and her team have done 22 research cruises to document the abundance and distribution of marine snow, which is a collection of small particles of detritus and dead plankton in the water column that clump together and sink rapidly to the sea floor. It turns out that the sticky clumps absorb oil and ferry it away to the deep sea. At the time, this was a huge surprise. 

"Oil normally floats," Daly said. "No one anticipated oil would sink to [the] sea floor."

Published results suggest that up to 14 percent of the oil spilled sank to the deep sea floor. Daly and her team are continuing to analyze how the abundance and distribution of marine snow changes over time and the relationship of marine snow with oil, so that future oil spill models can be developed that take this into account.

With years of data to analyze, Daly has no polar cruises on the immediate horizon, but you can bet it won't be too long until she is back out on the water. She and her colleagues are brainstorming how to take advantage of new observing systems in the North Pacific in combination with field samples. In the meantime, she has a kayak.

Representative Image Caption
AAAS Fellow Kendra Daly is a professor of biological oceanography at the University of South Florida. She spends a lot of her days researching zooplankton ecology. (Photo: Courtesy of USF)
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Laura Petersen