Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Potomac River: Ten-fold Increase in Native Submerged Vegetation Reflects Improved Water Quality

08.09.2010
The report, “Long-term reductions in anthropogenic nutrients link to improvements in Chesapeake Bay habitat is published in the Proceedings of the National Academy of Science.

The Potomac River in Washington, D.C. is showing multiple benefits from restoration efforts, newly published research suggests. Reduced nutrients and improved water clarity have increased the abundance and diversity of submerged aquatic vegetation (SAV) in the Potomac, according to direct measurements taken during the 18-year field study.

Since 1990, the area covered by SAV in the lower Potomac has doubled, the area covered by native SAV has increased ten-fold, the diversity of plant species has increased, and the proportion of exotic species to native species has declined as nutrients have declined, according to the study by the U.S. Geological Survey and England’s National Oceanography Centre (NOC) in Southhampton, UK.

“Improvements to plant communities living at the bottom of the river have occurred nearly in lock step with decreases in nutrients and sediment in the water and incremental reductions in nitrogen effluent entering the river from the wastewater treatment plant for the Washington DC area,” said USGS scientist Dr. Nancy Rybicki.

More than a dozen species of SAV, including the exotic hydrilla, co-exist in this reach of the Potomac that was almost barren in a 1978-1981 USGS study.

“People want to know that money spent on ecosystem restoration is having tangible results, but many feel that efforts to clean up Chesapeake Bay have so far had limited success,” said researcher Dr Henry Ruhl of the NOC.

“Upgrades to the wastewater treatment plant have benefited SAV habitats 50-miles downstream. These findings underscore the benefits of nutrient reduction efforts on a major tributary to the Chesapeake Bay,” said Rybicki, who has been conducting research on the Potomac since 1979.

“Our results suggest that widespread recovery of submerged vegetation abundance and diversity can be achievable if restoration efforts are enhanced across the bay,” said Henry Ruhl of the National Oceanography Centre. “There are many other estuaries globally where nutrients have been identified as contributing to SAV habitat decline, so restoration is an issue for many governments.”

SAV are critical to the ecosystem in the Chesapeake Bay and its tributaries. They provide oxygen, food, and shelter so that invertebrates, fish, crabs and waterfowl can survive. High nutrient levels stimulate algal blooms in the water, decrease water clarity, and block light needed for SAV growth.

The authors analyzed measurements of aquatic plant species abundance, nutrient effluent from the wastewater treatment plant, and water quality from 1990 to 2007. The surveys included a 50-mile reach of the tidal Potomac downstream from Washington.

Key Findings on the Potomac River’s SAV:

Native SAV cover increased tenfold from 288 to 3081 acres.

The overall area covered by SAV in the Potomac more than doubled since 1990, increasing from 4207 to 8441 acres.

The diversity of SAV has increased. In 1990 the exotic hydrilla was 10 times more abundant than any other species. In 2007 the abundance of the 7 most frequently occurring species are more evenly matched.

In 1990, more than 80% of the total SAV was hydrilla; in 2007 hydrilla declined to 20%.

Results suggest declining fitness of exotic species relative to native species during restoration.

These results are consistent with a multi-agency study released in July, which correlated nutrient reductions with gains in the abundance of SAV in some Chesapeake Bay tributaries, while noting a negative correlation within the bay between SAV and nitrogen.

The study was supported by USGS National Research Program; U.S. Army Corps of Engineers, Baltimore; the Metropolitan Washington Council of Government’s Aquatic Plant Management Program; and the Fisheries Division of the District of Columbia Department of Health.

Diane Noserale | EurekAlert!
Further information:
http://www.usgs.gov

More articles from Earth Sciences:

nachricht World’s oldest known oxygen oasis discovered
18.01.2018 | Eberhard Karls Universität Tübingen

nachricht A close-up look at an uncommon underwater eruption
11.01.2018 | Woods Hole Oceanographic Institution

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Polymers Based on Boron?

18.01.2018 | Life Sciences

Bioengineered soft microfibers improve T-cell production

18.01.2018 | Life Sciences

World’s oldest known oxygen oasis discovered

18.01.2018 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>