Posted on August 26, 2012 by Bob Berwyn
Less runoff, less nutrients equal smaller hypoxic area
A 2010 NOAA map shows the extent of that year’s dead zone at more than 7,700 square miles.
By Summit Voice
SUMMIT COUNTY — This year’s severe drought, centered in the Midwest, cut runoff and nutrient loading into the Mississippi and the Gulf of Mexico, result in the smallest dead zone in the Gulf in several years.
Texas A&M Oceanography professor Steve DiMarco cruised more than 1,200 miles in the Gulf in mid-August to measure this year’s oxygen-starved area, finding that only about 1,500 square miles affected by hypoxia, mostly near the Mississippi River delta off the coast of Louisiana. (more…)
Filed under: climate and weather, Drought, Environment, Marine biology, ocean conservation | Tagged: 2012 drought, Gulf of Mexico dead zone, Gulf of Mexico hypoxia, marine conservation, Mississippi River, oceans | 2 Comments »
Posted on June 19, 2011 by Jenney Coberly
2011 hypoxic zone to be affected by extreme Mississippi River flooding
2010 Gulf of Mexico hypoxic zone showing dissolved oxygen contours. Click on the map to go to the NOAA hypoxia watch page.
By Summit Voice
SUMMIT COUNTY — The 2011 hypoxic dead zone zone in the Gulf of Mexico is predicted to be the largest ever recorded due to extreme flooding of the Mississippi River this spring, according to an annual forecast by a team of NOAA-supported scientists from the Louisiana Universities Marine Consortium, Louisiana State University and the University of Michigan.
Along with replenishing soil in the river corridor, the massive flooding washes enormous amounts of nutrients to the sea. Seventy percent of nutrient loads that cause hypoxia are a result of agricultural runoff caused by rain washing fertilizer off of the land and into streams and rivers. Additionally, 12 million people live in urban areas that border the Mississippi, and these areas constantly discharge treated sewage into rivers.
Scientists are predicting the dead zone could measure between 8,500 and 9,421 square miles, or an area about the size of New Hampshire. If it does reach those levels it will be the largest since mapping of the Gulf dead zone began in 1985. The largest hypoxic zone measured to date occurred in 2002 and encompassed more than 8,400 square miles.
“While there is some uncertainty regarding the size, position and timing of this year’s hypoxic zone in the Gulf, the forecast models are in overall agreement that hypoxia will be larger than we have typically seen in recent years,” said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator.
Filed under: Environment, Marine biology | Tagged: dead zone, Environment, Gulf of Mexico dead zone, hypoxic zone, Mississippi flooding, ocean dead zones, ocean hypoxia, Summit County News | 6 Comments »