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:4/3/2017)... 2017  Data captured by IsoCode, IsoPlexis ... a statistically significant association between the potency ... and objective response of cancer patients post-treatment. ... whether cancer patients will respond to CAR-T ... as to improve both pre-infusion potency testing and ...
(Date:3/30/2017)... 30, 2017 Trends, opportunities and forecast in ... by technology (fingerprint, AFIS, iris recognition, facial recognition, hand ... by end use industry (government and law enforcement, commercial ... banking, and others), and by region ( North ... Asia Pacific , and the Rest of ...
(Date:3/27/2017)... ROCKVILLE CENTRE, N.Y. , March 27, 2017 ... by Healthcare Information and Management Systems Society (HIMSS) ... Analytics Outpatient EMR Adoption Model sm . In ... top 12% of U.S. hospitals using an electronic ... recognized CHS for its high level of EMR ...
Breaking Biology News(10 mins):
(Date:4/20/2017)... 20, 2017  Eli Lilly and Company (NYSE: ... galcanezumab for the prevention of migraine at the American ... place April 22-28, 2017, in Boston ... at AAN, including safety and patient outcomes data for ... a reduction in monthly migraine headache days among patients ...
(Date:4/20/2017)... ... April 20, 2017 , ... NetDimensions appoints Bill Mastin, a learning technology ... years of experience in the learning technologies industry, Mastin joins NetDimensions from the New ... Group plc (LTG). At LEO, Mastin served as SVP of the North America offices ...
(Date:4/20/2017)... ... April 20, 2017 , ... Parallel6™ , the leader in ... today that they were named one of the 2017 Top 10 eClinical Trial ... in the pharmaceutical industry. , “We take pride in honoring Parallel6 as one of ...
(Date:4/20/2017)... and PETACH TIKVAH, Israel , April ... leading developer of adult stem cell technologies for neurodegenerative diseases, ... will present at the Alliance for Regenerative Medicine,s (ARM) 5 ... Thursday, April 27, 2017 at 09:40 EDT in ... Kern , MD, MHSc, Chief Medical Officer & Chief Operating ...
Breaking Biology Technology: