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Marcia McNutt: Sea Science Essential for Managing Climate Changes, Human Health Risks

SAN DIEGO--Trace a finger along a geological map of the California coastline, and you'll travel a landscape rich in detail--until you hit the water. In our maps and in our minds, the oceans for too long have been a "featureless blue plain," said Marcia McNutt at the 2010 AAAS Annual Meeting.

As the first woman director in the 130-year history of the U.S. Geological Survey (USGS), McNutt hopes to erase that blank spot and replace it with a clearer picture of how the oceans are changing and how those changes could affect the whole country.

The lack of information, said McNutt in her 21 February plenary speech, has led to a "misinterpretation of the ocean being boundless in resources and perhaps trivial in our ability to engineer it."

The ocean acreage managed by the U.S. Department of the Interior is five times the size of the land under its care. As part of the Department, McNutt said, the USGS provides the science input that guides that management.


Marcia McNutt

Before her appointment as director, McNutt was the president and chief executive officer of the Monterey Bay Aquarium Research Institute. She received her Ph.D. in earth sciences from the Scripps Institution of Oceanography in 1978.

McNutt said that one of the biggest tasks before the USGS is studying the effects of global climate change on sea level rise. Melting glaciers and expanding warmer waters are often considered the worst culprits, she said, calling it the "filling up the bathtub scenario."

The USGS does monitor glacier melt with satellite observations from its LANDSAT program, said McNutt, but they also study factors that could have more immediate and dramatic effects on sea level.

For instance, the sudden shift in tectonic plates underneath Haiti during January's  7.0 magnitude earthquake "gave a sense of motion that the oceans went up and the mountains went down," said McNutt.

The result, she said, was "about 500 years worth of sea level rise in seconds."

In the United States, the effects of sea level rise differ from shore to shore, according to USGS research. The rocky coasts of Maine and California's Big Sur are "relatively armored" against erosion, said McNutt, but beaches in parts of Florida, the Gulf Coast, and the Atlantic seaboard are much more vulnerable to slipping away into the seas.

McNutt said the first USGS maps of these differences "were not on a fine enough scale for individuals or communities to act on it." More recent maps have placed the problem in stark relief for certain communities. Shorelines in Alaska, left unprotected after their usual cover of stable Arctic ice melted away in a series of hot summers, retreated as much as 13 meters (42 feet) a year between 2002 and 2007.

The USGS also keeps a close watch on the health of the oceans, in particular the bloom of  "dead zones" like the one in the Gulf of Mexico. Growing to the size of the state of New Jersey each year, the oxygen-deprived waters of the dead zone can devastate fisheries and oyster beds.

USGS research has traced the origins of the Gulf dead zone back to 1910, discovering that it was well-established by the 1930s. The long history could help scientists understand why the dead zone is worse in some years than in others, said McNutt.

The Survey doesn't study fish, but its researchers also study how mercury in the oceans is converted to methylmercury, a neurotoxin found at harmful levels in some seafood. Methylmercury levels in the United States have fallen since the 1990, but rising mercury emissions in Asia and Africa continue to pollute with far-reaching impacts. McNutt said North Pacific seawater "may double in methylmercury levels by 2050."

Once considered one of the premier science agencies in the U.S., the USGS "has struggled mightily to maintain its presence" in the face of decades of budget cuts, said McNutt. Although the president's 2011 budget adds $4 million to the Survey budget, McNutt said her greatest challenge as director is to restore the USGS to its leadership role.


Becky Ham

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