Small streams remove more nutrients such as nitrogen from water than do their larger counterparts, according to researchers who have applied sampling methods developed in a National Science Foundation (NSF) Arctic area ecological study to waterways across the nation. The finding could have important implications for land-use policies in watersheds from the Chesapeake Bay on the East Coast to Puget Sound in the West.

The findings, to be published in the April 6 edition of Science, are based on data collected initially from streams in NSF's Arctic Tundra Long-Term Ecological Research (LTER) site in Alaska. Excess nitrogen can cause ecologically damaging effects in large waterways, include algeal blooms, because the nutrients are transported downstream and collect there.

"There's a very strong relationship between the size of a stream and how rapidly that stream removes nutrients," said Bruce Peterson of the Ecosystems Center at the Marine Biological Laboratory in Woods Hole, Mass. "The smaller the stream, the more quickly nitrogen can be removed and the less distance it will be transported down the stream."

Peterson is one of more than a dozen researchers who contributed to the Science paper.

He noted that the findings are unique because they were produced by research teams working in a coordinated and identical fashion nationwide under the same research protocol.

"In terms of ecosystems studies it's very rare to get people from this many sites to agree to do this kind of controlled experiment," Peterson said. "Many people study nitrogen cycling, but they all tend to do their own experiments. Collaboration is the key to developing a general understanding of ecosystems."

Peterson notes that, collectively, the new studies provide a radically different picture of the role of small streams in contributing to existing nutrient loading. "Traditionally streams have b
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Contact: Peter West
pwest@nsf.gov
703-292-8070
National Science Foundation
5-Apr-2001