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:6/3/2016)... Das DOTM (Department ... hat ein 44 Millionen $-Projekt ... einschließlich Personalisierung, Registrierung und IT-Infrastruktur, an Decatur ... Implementierung von Identitätsmanagementlösungen. Zahlreiche renommierte internationale Anbieter ... aber Decatur wurde als konformste und innovativste ...
(Date:6/2/2016)... The Weather Company , an IBM Business (NYSE: IBM ... which consumers will be able to interact with IBM Watson ... or text and receive relevant information about the product or ... long sought an advertising solution that can create a one-to-one ... valuable; and can scale across millions of interactions and touchpoints. ...
(Date:6/1/2016)... 1, 2016 Favorable Government Initiatives ... and Criminal Identification to Boost Global Biometrics System Market ... TechSci Research report, " Global Biometrics Market By ... and Opportunities, 2011 - 2021", the global biometrics market ... on account of growing security concerns across various end ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... 27, 2016  Liquid Biotech USA ... of a Sponsored Research Agreement with The University ... (CTCs) from cancer patients.  The funding will be ... correlate with clinical outcomes in cancer patients undergoing ... then be employed to support the design of ...
(Date:6/24/2016)... ... 24, 2016 , ... While the majority of commercial spectrophotometers and fluorometers use ... 6000i models are higher end machines that use the more unconventional z-dimension of 20mm. ... from the bottom of the cuvette holder. , FireflySci has developed several Agilent ...
(Date:6/23/2016)... CAMBRIDGE, Mass. , June 23, 2016 /PRNewswire/ ... the development of novel compounds designed to target ... compound, napabucasin, has been granted Orphan Drug Designation ... in the treatment of gastric cancer, including gastroesophageal ... cancer stemness inhibitor designed to inhibit cancer stemness ...
(Date:6/23/2016)... MA (PRWEB) , ... June 23, 2016 , ... ... Peel Plate® YM (Yeast and Mold) microbial test has received AOAC Research Institute ... platform of microbial tests introduced last year,” stated Bob Salter, Vice President of ...
Breaking Biology Technology: