Antarctica is Changing as Climate Warms

Scientists who have been going to Antarctica regularly have noticed unmistakable signs that the continent is changing as the climate warms. No place is showing a larger winter warming than the northwest coast of the Antarctic Peninsula – the long arm of the continent that reaches northward

toward South America. Rutgers researchers and students from the Institute of Marine and Coastal Sciences  have been busy over the Antarctic summer documenting and reporting those changes.

A March 13, 2009 article in Science documents for the first time that phytoplankton, the base of the food chain, are diminishing off the northwestern Antarctic Peninsula and increasing southward. Lead author Martin Montes-Hugo, a postdoctoral scholar in the institute's Coastal Ocean Observation Laboratory (COOL) analyzed 30 years of satellite and field data showing phytoplankton decreasing in the north by 12 percent, while increasing in the south.

Among Montes-Hugo's co-authors are Oscar Schofield, professor of marine science and co-director of COOL and Hugh Ducklow of the Marine Biological Laboratory in Woods Hole, Mass.

"We are showing for the first time that there is an ongoing change in phytoplankton concentration and composition along the western shelf of the Antarctic Peninsula that is associated with a long-term climate modification," Montes-Hugo said. "These changes may explain in part the observed decline of some penguin populations."

The main food of these Adelie penguins is krill, tiny crustaceans that depend, in turn, on phytoplankton. Krill have been diminishing off the northwest Antarctic Peninsula and increasing in the south. The absence of their food source has been suggested to explain the observed declines in the Adelies, that once nested in their tens of thousands on islands near the United States research base at Palmer Station.

Researchers have known that larger animals, such as Adelie penguins, have been diminishing near the research station. Schofield, who has been going there since his graduate student days nearly two decades ago, has seen the change up close. "Ecologists working at Palmer have documented declines from close to 15,000 breeding pairs of Adelies in the mid 1970s to about 3,000 pairs at Palmer Station today," he said.

"Now we know that climate changes are impacting at the base of the food web and forcing their effects on up through the food chain," said Ducklow, of the Marine Biological Laboratory. "Martin Montes-Hugo's elegant work, utilizing different satellite streams of data, nailed that down."
The paper in Science is based on satellite sources and field data from scientists like Schofield, who have been going to Antarctica regularly for many years. The National Science Foundation sponsors a summer cruise each January, and Schofield, like most researchers who have a place in that cruise, regularly takes graduate students. This year, he also took some undergraduate students, including Mike Garzio, a senior from Hamilton, N.J., majoring in ecology and natural resources and minoring in marine science.

"It was my first real research cruise and real field work, and I'm grateful to Dr. Schofield for asking me to join him," Garzio said. "I want to stay in academia my entire life and do research, so a chance to be part of a team researching climate change effects in the most rapidly changing was great for me."