Navigation Links
Streams natural filters, if not overloaded
Date:3/12/2008

Blacksburg, Va. Streams are natural filters that help remove and transform pollutants that drain from surrounding watersheds, including excess nitrogen from human activities. Scientists know this as a result of many hours of getting their hands if not dirty, at least very wet -- monitoring streams nationwide.

Nitrogen removal in streams is important because it reduces the potential for eutrophication the excessive growth of algae and aquatic plants in downstream lakes and coastal marine waters, said Jack Webster, professor of biology at Virginia Tech. Eutrophication in the Chesapeake Bay has damaged the oyster industry in Virginia and in the Gulf of Mexico, the Mississippi River has created a vast zone of oxygen depletion with adverse effects on fisheries.

Webster, two of his Virginia Tech colleagues, and four former Virginia Tech students are among 31 authors of an article in the March 13 issue of Nature that reports the researchers findings on how stream systems are able to remove nitrogen.

The study, lead by Oak Ridge National Laboratory (ORNL), looked at 72 streams in the U.S. and Puerto Rico over the course of three years. Virginia Techs Stream Team conducted measurements on nine streams in North Carolina including forest streams in the southern Appalachian Mountains, agricultural streams where they had to protect equipment from curious cows, and urban streams, including one that ran through a golf course and another that ran through a construction site. Eight other teams worked at the other 63 streams.

The research process meant 24-hour monitoring. The Stream Team involvement was very important, said Webster.

In the first phase of the study, the scientists added small amounts of a non-radioactive isotope of nitrogen to streams as nitrate, the most prevalent form of nitrogen pollution. They then measured how far downstream the nitrate traveled and how what processes removed it from the water.

The scientists found that the nitrate was taken up from stream water by algae and microorganisms. In addition, a fraction was permanently removed from streams by denitrification, a bacterial process that converts nitrate to nitrogen gas, which harmlessly joins an atmosphere already predominantly composed of nitrogen gas.

In the second phase of the study, the scientists developed a model that predicts nitrate removal as water flows through small streams and into larger streams and rivers. Our model showed that the entire stream network is important in removing pollution from stream water, said Patrick Mulholland, lead author of the study, a member of ORNLs Environmental Sciences Division, and a faculty member at the University of Tennessee. In addition, the effectiveness of streams to remove nitrate was greatest if the streams were not overloaded by pollutants such as fertilizers and wastes from human activities.

The largest removal occurred when nitrate entered small healthy streams and traveled throughout the network before reaching large rivers. The scientists concluded from their research that streams and rivers are effective filters that help reduce the amount of nitrate pollution exported from landscapes and thereby reduce eutrophication problems, Webster said.


'/>"/>

Contact: Susan Trulove
STrulove@vt.edu
540-231-5646
Virginia Tech
Source:Eurekalert  

Related biology news :

1. Greenhouse gas from English streams
2. New research offers prioritization plan for reducing nutrient pollution in feeder streams
3. Salamanders, headwater streams critical in food chain
4. Scientists show that streams are critical to preservation of oceanic coastal zones
5. Small streams mitigate human influence on coastal ecosystems
6. From the backyard to the ocean: New study shows streams act as key nitrogen filters
7. Streams remove significant amounts of nitrogen, preventing downstream dead zones
8. Natural chemical found in broccoli helps combat skin blistering disease
9. Natural insecticide re-created in the lab
10. Researchers develop simple method to create natural drug products
11. Brains timing linked with timescales of the natural visual world
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Streams natural filters, if not overloaded
(Date:6/9/2016)... , June 9, 2016 ... deploy Teleste,s video security solution to ensure the safety of ... during the major tournament Teleste, an ... systems and services, announced today that its video security solution ... to back up public safety across the country. The ...
(Date:6/2/2016)... 2016   The Weather Company , an IBM Business ... industry-first capability in which consumers will be able to interact ... questions via voice or text and receive relevant information about ... Marketers have long sought an advertising solution that can ... personal, relevant and valuable; and can scale across millions of ...
(Date:5/20/2016)... May 20, 2016  VoiceIt is excited to ... VoicePass. By working together, VoiceIt and ... VoiceIt and VoicePass take slightly different approaches to ... both security and usability. ... this new partnership. "This marketing and ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... June 27, 2016 , ... Rolf ... join the faculty of the University of North Carolina Kenan-Flagler Business School ... and entrepreneurship at UNC Kenan-Flagler, with a focus on the school’s international efforts, ...
(Date:6/24/2016)... Brooklyn, NY (PRWEB) , ... June 24, 2016 , ... ... 15mm, machines such as the Cary 5000 and the 6000i models are higher end ... height is the height of the spectrophotometer’s light beam from the bottom of the ...
(Date:6/23/2016)... , June 23, 2016 /PRNewswire/ - FACIT ... Ontario biotechnology company, Propellon Therapeutics ... development and commercialization of a portfolio of first-in-class ... Epigenetic targets such as WDR5 represent an exciting ... significantly in precision medicine for cancer patients. Substantial ...
(Date:6/23/2016)... 2016  The Biodesign Challenge (BDC), a university competition ... harness living systems and biotechnology, announced its winning teams ... New York City . The ... projects at MoMA,s Celeste Bartos Theater during the daylong ... senior curator of architecture and design, and Suzanne ...
Breaking Biology Technology: