Potomac River: 10-fold increase in native submerged vegetation reflects improved water quality

 

ScienceDaily (Sep. 7, 2010) — 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." …

Potomac River: 10-fold increase in native submerged vegetation reflects improved water quality

Technorati Tags: environmental restoration,sewage,nitrogen,eutrophication,dead zone

Canada approves Enviropig™ -- piglets inherit genetic modifications for cleaner manure

 Image: Scott Bauer, ARS.USDA

Piglets Inherit Genetic Modification Canada has approved limited production of animals dubbed "enviropigs™," a genetically modified breed of pigs producing up to 65% less phosphorous in pig poo and urine. The pigs pass the genetic modification along to their young, as well. The very idea that a genetically modified animal rates the moniker "enviro-" points to the severity of the issue addressed by the science behind these pigs. Phosphorous is a fertilizer. Phosphorous in animal and human wastes runs off or discharges to surface waters, where it spurs large algal blooms. The algae use up the oxygen in the water, leaving behind a "dead zone," an area of lake, river, or ocean where nothing can live due to the hypoxic conditions. …

Canada Approves Enviropig™, Piglets Inherit Genetic Modifications for Clean Manure

Technorati Tags: biotechnology,genetic engineering,anoxia,eutrophication

New tool fertilizes fields and reduces runoff nutrients

A new field tool developed by Agricultural Research Service scientists applies poultry litter to fields in shallow bands, reducing runoff of excess nutrients like phosphorus and nitrogen.

Poultry litter—a combination of poultry manure and bedding material, such as pine shavings or peanut or rice hulls—is a natural fertilizer. The conventional method of applying it to fields utilizes a broadcast spreader, which scatters the litter across the soil surface. Because it rests on top of the soil, the litter is vulnerable to runoff in heavy rains.

A new tool developed by ARS agricultural engineer Thomas R. Way and his colleagues at the agency's National Soil Dynamics Laboratory in Auburn, Ala., offers a solution. The tool digs shallow trenches about two to three inches deep in the soil. It then places the poultry litter in the trenches and covers it with soil. Burying the litter significantly reduces the risk of runoff.

New Tool Fertilizes Fields And Reduces Runoff Nutrients
Sun, 28 Dec 2008 05:00:00 GMT

Technorati Tags: eutrophication