The study, conducted during a three-year period by researchers from MSU, University of Tennessee and University of Notre Dame, focused on the roles small and large streams play in removing nitrogen from water.

The current processes used for dealing with nitrogen have room for improvement, Hamilton said.

“Obviously, it’s best to find ways to use nitrogen more efficiently for agriculture,” he said. “The way we do it now, at least, inevitably a lot of nitrogen leaks out.”

Researchers tracked nitrogen samples through streams in the Kalamazoo River basin and other rivers in the U.S. and Puerto Rico. Findings showed both small and large rivers are capable of reducing nitrogen levels through bacteria and other small organisms.

Nitrogen commonly enters the water supply through fertilizers and industrial exhaust and causes problems for humans and the environment.

While it is hazardous if ingested, especially for infants, it also leads to excessive algae growth in coastal areas, which consumes oxygen in the water, Hamilton said. This causes underwater life to die, which has already been seen in the Gulf of Mexico and the Mississippi River.

Bacteria within rivers also can convert nitrogen to nitrous oxide, a greenhouse gas and contributor to global warming.

Patrick Mulholland, a Tennessee professor who headed the study, said the problems many rivers face is representative of today’s environment.

“It means we better be careful in how we treat our stream networks, from the smallest streams to the larger rivers,” Mulholland said. “We’re overloading our stream networks and degrading our stream networks, channelizing them, putting in pipes, and we’re losing that service that stream networks provide.”

A similar study done in 1996 addressed the same question but involved fewer streams, said Jennifer Tank, an associate professor at Notre Dame who worked on the study. This study expanded on that research, she said.

“We couldn’t say a whole lot about nitrogen cycling and the role of streams in this if we only studied these pristine systems,” Tank said.

Hamilton hopes the study will bring awareness toward the role rivers and streams play in dealing with nitrogen levels.

“We hope that it makes people appreciate that streams are more than just pipes,” Hamilton said. “Anything that can reduce that nitrogen before it goes downstream … and causes problems is important.”