Tag Archives: woods hole

Ohnemus joins UGA Skidaway Institute faculty

Chemical oceanographer Daniel Ohnemus has joined the faculty of UGA Skidaway Institute of Oceanography and the UGA Department of Marine Sciences as an assistant professor.

Ohnemus received his bachelor’s degree from Williams College and his Ph.D. in chemical oceanography from the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution Joint Program. He joined UGA Skidaway Institute following a postdoctoral appointment at Bigelow Laboratory for Ocean Sciences in East Boothbay, Maine.

Ohnemus’ research focuses on marine particles—the mixture of living organisms and non-living chemicals that transport and transform material within the oceans.

“All living organisms need small ‘trace’ amounts of elements like iron and copper to live,” Ohnemus said. “Unlike on land where plants can get these elements from soil, algae in the oceans have to get them from much rarer things like dust, other cells or seawater itself. The limited availability of these elements is an important control on many marine ecosystems.”

The son of a lobsterman and an elementary school educator, Ohnemus grew up on Cape Cod and became fascinated with the ocean at a young age. In fourth grade, his class visited Woods Hole to take part in a satellite video call with marine scientists off the Galapagos Islands. Seeing underwater robots explore a coral reef got Ohnemus hooked on marine science.

At Williams College, he pursued a double major in biology and chemistry. After graduation, he returned to Woods Hole, first as a research technician and later as a graduate student. After earning his Ph.D., he completed a postdoctoral appointment at the Bigelow Laboratory for Ocean Sciences, continuing to concentrate on marine particles and trace elements.

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Death in the ocean keeps Skidaway Institute’s Harvey’s research alive

UGA Skidaway Institute of Oceanography scientist Elizabeth Harvey travels to the farthest reaches of the globe and in the nastiest weather to study microscopic marine plants known as phytoplankton. Last fall, Harvey spent a month on board a research ship in the turbulent North Atlantic as part of a NASA-funded project to learn more about these tiny organisms that are vital to life on the planet.

OLYMPUS DIGITAL CAMERAHarvey is one of UGA Skidaway Institute’s newest researchers, having joined the faculty in August of last year. Originally from Maine, she received her doctorate in oceanography from the University of Rhode Island and followed that with a position as a post-doctoral investigator at Woods Hole Oceanographic Institute. While she has a broad set of interests, phytoplankton have become the focus of her research.

“Phytoplankton are really important to a lot of different processes that impact life on Earth,” Harvey said. “They are at the bottom of the food chain so they are really important for feeding higher trophic levels like fish — and even higher — to whales really.”

Phytoplankton also play an important role in how nutrients and carbon are cycled around the world. It’s estimated that phytoplankton provide about 50 percent of the oxygen we breathe.

“So if you like breathing oxygen, you should like phytoplankton,” she said.

To study phytoplankton, she said, is to look into a world where lots of different interactions happen. Harvey’s work specifically focuses on the interactions between those single cell plants and the other organisms around them, including microzooplankton predators, bacteria and other phytoplankton. She hopes to better understand some of those individual interactions in order to make predictions on a larger scale.

“You wouldn’t think a single cell could be so dynamic, but phytoplankton are really complex,” Harvey said. “Rumor is NASA once took a look at one particular class of phytoplankton to see if they were extra-terrestrial.”

Using sensors on their cell surface, phytoplankton can sense their immediate surroundings — detecting organisms around them, sensing predators and modifying their behavior to escape predation. Some also produce toxic compounds in self-defense.

“Amazingly, they have very specific but very important interactions with other organisms,” she said. “You wouldn’t think a single cell could to that, but they do, and it can have some large-scale consequences.”

Last fall’s cruise on board the Woods Hole Research Vessel Atlantis was part of the NASA-sponsored North Atlantic Aerosols and Marine Ecosystems Study, or NAAMES. It was the first of a series of cruises to study an annual spring phytoplankton bloom in the North Atlantic. Harvey was one of 32 scientists on board. Her particular role was to measure phytoplankton mortality by both looking at the rate that phytoplankton were subject to predation or “grazing” by microzooplankton and also mortality due to viruses.

“I like to try to get people’s attention by telling them I am interested in death, which I sort of am,” Harvey said. “I am interested in how phytoplankton die.”

Understanding the relationship of phytoplankton mortality due to grazing compared to viral infections is important when trying to understand how carbon flows through marine ecosystems. The carbon from phytoplankton cells consumed by microzooplankton may continue to travel up the food web, while carbon from phytoplankton killed by viruses fuels the growth of other microbes, or could result in carbon sinking to the deep ocean.

Cruising the North Atlantic in November was no picnic. Harvey recalled 30-foot seas and 50-knot winds.

“That was a little adventurous,” she said. “We couldn’t do deck work. I didn’t tell my parents or husband about that.”

However, at 274 feet long and displacing more than 3,500 tons, the R/V Atlantis is a fairly large research ship, and Harvey says she never felt unsafe.

The days frequently started at 4 a.m. when scientists would lower an instrument package over the side to measure ocean conditions like salinity and temperature and to collect water samples. The scientists would work until eight or nine in the evening before catching some sleep and starting again the next morning.

“It’s a lot of long, hard work, but, on the other hand, your life becomes very simple,” she said. “The commitments in your normal life fade away. Someone even cooks your food for you every day.

“You work for long hours, but in the scheme of things, that is what you are there to do. There are no other distractions.”

Harvey says she was very happy to be part of the science team on the first cruise of the NAAMES project, and she enjoyed working with the other scientists on board.

“Everyone was very collegial and thrilled to be a part of a really cool project,” she said. “Scientists always like to get data, so sometimes I think that if I can be collecting new data, I am happy.”

Diaz joins UGA Skidaway Institute faculty

Marine biogeochemist Julia Diaz has joined the faculty of the University of Georgia Skidaway Institute of Oceanography as an assistant professor.

OLYMPUS DIGITAL CAMERAOriginally from Alpharetta, Ga., Diaz was graduated summa cum laude from the University of Georgia with a B.S. in biology and went on to earn her Ph.D. in earth and atmospheric sciences from Georgia Tech. She conducted postdoctoral research at Harvard University and the Woods Hole Oceanographic Institution.

Diaz’s research examines how the chemistry and microbiology of the oceans shape each other and, ultimately, how this interaction affects ecosystem health from local to global scales. She is currently studying the chemical basis of coral bleaching, a devastating consequence of global warming which threatens coral reefs worldwide.

“I also study how microscopic plantlike organisms acquire the chemical nutrients they need to survive in extremely nutrient-poor areas of the ocean and how these processes may affect ecosystem structure and climate,” she said. “My research has taken me all over the world, from Antarctica to the Caribbean, and now I am very excited to explore new scientific questions along our beautiful coast and offshore waters.”

Harvey joins Skidaway Institute faculty

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Biological oceanographer Elizabeth Harvey has joined the faculty of the UGA Skidaway Institute of Oceanography as an assistant professor.

Harvey received her bachelor’s degree in marine science from the University of Maine and a master’s in environmental science from Western Washington University. She earned her doctorate in oceanography from the University of Rhode Island. Immediately prior to joining Skidaway Institute, she completed a post-doctoral fellowship at Woods Hole Oceanographic Institution.

Harvey’s research focus is on the mechanisms of mortality in the planktonic environment in the ocean and how that influences food web structure and biogeochemical cycling.