Navigation Links
Small streams mitigate human influence on coastal ecosystems

Healthy streams play a major role in minimizing the amount of human-generated pollutants, such as nitrogen, that are delivered downstream. This ecosystem service is valuable; excess nitrogen degrades lakes and coastal oceans by stimulating algal blooms and depleting the water of oxygen. This phenomenon, also known as eutrophication, threatens fisheries around the world.

This week, a team of scientists that included Cary Institute ecologists Dr. Stuart E.G. Findlay and Dr. Amy Burgin published a Nature paper cautioning against policies and practices that result in intensive nitrogen loading to streams. Thirty-one researchers participated in the effort, which was headed by Dr. Patrick Mulholland of the Oak Ridge National Laboratory. Their recommendation is based on findings that stream networks are effective nitrogen filters, but they cannot keep pace when they are directly overloaded by nitrogen from fertilizer or human waste.

Using a non-radioactive nitrogen isotope (N-15), the research team traced the fate of nitrate additions in 72 streams across multiple land use conditions (e.g., urban, agricultural, natural conditions) in the continental U.S. and Puerto Rico. The tracer let scientists measure how far the nitrate traveled and what processes removed it from the water. At low-to-moderate addition levels, streams were effective at minimizing nitrate export downstream; under high-loading rates this efficiency collapsed.

Within the streams, nitrate was removed by two pathways. It was taken from the stream water by tiny aquatic organisms, such as algae, fungi, and bacteria. Or it was permanently removed by a bacterial process called denitrification. This occurs when microbes in the stream bed convert nitrate to nitrogen gas (N2), allowing it to return in an inert form to the atmosphere

The researchers also developed a model that predicts nitrate removal as water flows from small streams to larger rivers, and ultimately the ocean. The model showed that removal was most effective when nitrate entered small healthy streams and traveled through a stream network before reaching larger water bodies. Participants concluded that, by minimizing the amount of nitrogen pollution exported downstream, streams play a key role in reducing eutrophication in lakes and coastal waters.

By protecting and restoring stream ecosystems, we can maintain or enhance their nitrogen removal capabilities. But, as with any service, overuse can lead to failure. Findlay notes, We should be cautious about using a streams cleansing ability to solve human-generated water quality problems. It is akin to treating the symptoms of a problem rather than the underlying cause, which includes intense agricultural practices and poorly planned development. Our results show streams can help us use natural resources, but this capacity has its limits.


Contact: Lori Quillen
Institute of Ecosystem Studies

Related biology news :

1. Penn engineers create carbon nanopipettes that are smaller than cells and measure electric current
2. Iowa State researchers look for smaller, cheaper, 1-dose vaccines
3. Small RNA plays parallel roles in bacterial metabolism
4. Identification of a novel class of (not-so) small RNAs
5. Sweet potato shines as new promise for small enterprise and hunger relief in developing countries
6. Small-scale fishing in Mexico rivals industrial fisheries in accidental turtle deaths
7. Research shows loggerhead sea turtles threatened by small-scale fishing operations
8. Cilia: small organelles, big decisions
9. 2007 ozone hole smaller than usual
10. New molecular clock from LLNL and CDC indicates smallpox evolved earlier than believed
11. Handbook of small grain insects available now
Post Your Comments:
Related Image:
Small streams mitigate human influence on coastal ecosystems
(Date:5/24/2016)... facilitates superior patient care by providing unparalleled technology to leaders of the medical imaging ... product recently added to the range of products distributed by Ampronix. Photo ... ... ... News ...
(Date:5/12/2016)... DALLAS , May 12, 2016 ... has just published the overview results from the Q1 ... of the recent wave was consumers, receptivity to a ... wearables data with a health insurance company. ... choose to share," says Michael LaColla , CEO ...
(Date:4/28/2016)... and BANGALORE, India , April 28, 2016 ... a product subsidiary of Infosys (NYSE: INFY ), ... a global partnership that will provide end customers ... mobile banking and payment services.      (Logo: ... innovation area for financial services, but it also plays a ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... , June 24, 2016 Epic ... sensitively detects cancers susceptible to PARP inhibitors by ... tumor cells (CTCs). The new test has already ... therapeutics in multiple cancer types. Over ... DNA damage response pathways, including PARP, ATM, ATR, ...
(Date:6/23/2016)... ... June 23, 2016 , ... Mosio, a ... eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering with experienced clinical research ... by providing practical tips, tools, and strategies for clinical researchers. , “The landscape ...
(Date:6/23/2016)... - FACIT has announced the creation of a ... Propellon Therapeutics Inc. ("Propellon" or "the Company"), to ... of first-in-class WDR5 inhibitors for the treatment of ... an exciting class of therapies, possessing the potential ... patients. Substantial advances have been achieved with the ...
(Date:6/23/2016)... ... June 23, 2016 , ... Charm Sciences, Inc. is ... has received AOAC Research Institute approval 061601. , “This is another AOAC-RI approval ... Bob Salter, Vice President of Regulatory and Industrial Affairs. “The Peel Plate methods ...
Breaking Biology Technology: