ORONO – A University of Maine graduate student has received one of eight 2003 Canon National Park Science Scholarships awarded in September to students studying at national parks in North and South America.

Sarah Nelson, a researcher at UM’s Sen. George J. Mitchell Center for Environmental and Watershed Research, will use the $78,000 three-year scholarship to analyze winter trends in watershed chemistry at Acadia National Park.

Nelson earned a master’s degree at UM last year and is working toward a doctorate in UM’s ecology and environmental sciences program. For two years, she was part of a team working at Acadia to understand how mercury and nitrogen in streams and precipitation relate to the natural features and history of the landscape.

Officials said these were national issues of concern to the National Park Service, for which Acadia has provided a natural laboratory for many years. The research effort is ongoing and focuses on the Cadillac Brook watershed on Cadillac Mountain and on the Hadlock Brook watershed near the town of Northeast Harbor.

In her role, Nelson carried plastic tubing, bottles and other research equipment up mountains and along stream banks. She analyzed water samples and produced a thesis on the influence of water percolating through the tree canopy on water chemistry in streams. Trees can scavenge the toxic metal mercury and acid rain components from the atmosphere, she and her colleagues found, and play an important role in watershed processes that result in mercury accumulation in fish.

Since all of that research was done during the growing season, Nelson said, the resulting picture is incomplete. Now she will focus on how mercury and other chemicals accumulate on Acadia’s landscape during the winter. She will collect information about the chemistry of winter precipitation as well as mercury in streams to develop a more complete understanding of watershed processes.

“A lot of winter storms blow in off the ocean, as opposed to the rest of the year, when they tend to come across inland areas. We may be missing the effect of winter storms on watersheds,” Nelson said.

Mercury in the atmosphere can come from natural sources in the ocean as well as human activities on land.

Nelson’s proposal for studying winter deposition of mercury was chosen from 140 applications and is the only 2003 project to be conducted in the United States. Other 2003 Canon scholars will work in Canada, Argentina, Brazil, Peru and Mexico.

“The goal of the program is to train the next generation of conservation scientists,” said Gary Machlis, University of Idaho professor and program coordinator for the Canon National Parks Science Scholars Program. “We see these students as future leaders in conservation science.”

Nelson grew up in Berlin, Mass., and after briefly studying science and civil engineering, received a bachelor’s degree in art history from Columbia University in New York City.

She became interested in environmental science, she said, after working as a volunteer to monitor water quality in the Assabet River, which flows through Berlin.

A desire to learn more about water quality and forests led Nelson to UM, where, as a student technician in the environmental chemistry laboratory, she participated in ongoing research at Acadia.

“Sarah has both a natural curiosity and the drive to find ways to get things done,” said her principal adviser, Steve Kahl, director of the Mitchell Center. “Her entrepreneurial spirit is a key part of the success of the center.”

Past research at UM and elsewhere, Nelson said, has focused on mercury in fish and other organisms. “At this point, scientists are trying to figure out where the fish are getting the mercury,” she said. To get at that question, Nelson will sample winter precipitation for chloride, sodium and sulfate mercury to gauge the impact of winter weather on Acadia’s watersheds.

“Different amounts of all of these chemicals come from the land and the ocean, and it will be interesting to see which ones spike up during the winter, compared to the rest of the year, and which ones don’t,” Nelson said.

Nelson will continue to collaborate with other scientists from UM and the Institute of Ecosystem Studies in Millbrook, N.Y., which also has conducted environmental studies in the park. Their eventual goal is to create a scientific model of atmospheric deposition that can be used to predict stream water quality on the basis of weather, vegetation and other factors.

Nelson and Kahl are co-editing an upcoming special issue of the journal Environment Monitoring and Assessment on watershed research at Acadia.

The Canon National Park Science Scholars Program is supported by Canon USA, Inc., the American Association for the Advancement of Science and the National Park Service.