Search OCA:
Get Local!

Find Local News, Events & Green Businesses on OCA's State Pages:

OCA News Sections

Organic Consumers Association

Mississippi Basin Water Quality Declining Despite Conservation

For Related Articles and More Information, Please Visit OCA's CAFO's vs. Free Range Page.

U.S. federal scientists say water quality has declined in the massive Mississippi River Basin in recent years due to the combined effects of agricultural and urban infrastructure, despite decades of conservation efforts. That's a concern both for those who rely on the river system and for those downstream on the Gulf of Mexico, where a huge "dead zone" hurts fishing and recreational opportunities.

Scientists with the U.S. Geological Survey (USGS) sampled the main stem and four tributaries of the Mississippi River and found that levels of nitrate increased at more than half the sites from 1980 to 2010. Overall, nitrate levels increased by 14 percent during that period, the USGS reported in a congressional briefing on Capitol Hill Friday.

The new findings are a warning about water quality health nationwide, and raise a troubling issue: even when policymakers and environmental advocates try to clean up the waterways, their efforts are not always successful.

Scientists often focus on levels of nitrate because it plays an important role in the environment. The nitrogen in nitrate is an essential nutrient for plants. But too much of it leads to overgrowths of algae, called blooms, which can use up too much oxygen in the water (a process called eutrophication), choke out fish and seagrasses, and in some cases release toxic chemicals.

Large algal blooms have created dead zones in Puget Sound, the Chesapeake Bay, Long Island Sound, and many other waterways. The Gulf of Mexico is now host to the world's second largest dead zone, a patch of impaired sea about the size of New Jersey. (Learn more about river basins.)

"When oxygen gets too low, most fish can't live there," says Nancy Rabalais of the Louisiana Universities Marine Consortium, who studies the dead zone. "They'll swim away if they can, but if they are associated with the bottom they can't." She points to declines in shrimp catches and charter fishing trips in the area and an estimated loss of $82 million a year.     


>>> Read the Full Article

For more information on this topic or related issues you can search the thousands of archived articles on the OCA website using keywords: