Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

U-M forecasters predict second-smallest Gulf of Mexico 'dead zone'

22.06.2012
A dry spring in portions of the Midwest is expected to result in the second-smallest Gulf of Mexico "dead zone" on record in 2012, according to a University of Michigan forecast released today.
The U-M prediction calls for a 2012 Gulf of Mexico dead zone of about 1,200 square miles, an area the size of Rhode Island. If the forecast is correct, 2012 would replace 2000 (1,696 square miles) as the year with the second-smallest Gulf dead zone. The smallest Gulf oxygen-starved, or hypoxic, zone was recorded in 1988 (15 square miles).

"While it's encouraging to see that this year's Gulf forecast calls for a significant drop in the extent of the dead zone, we must keep in mind that the anticipated reduction is due mainly to decreased precipitation in the upper Midwest and a subsequent reduced water flow into the Gulf," said aquatic ecologist Donald Scavia, professor at the U-M School of Natural Resources and Environment. "The predicted 2012 dead-zone decline does not result from cutbacks in nitrogen use, which remains one of the key drivers of hypoxia in the Gulf."

The U-M prediction is one of two Gulf dead zone forecasts released today by the National Oceanic and Atmospheric Administration, which funds the research. The other NOAA-supported team, from the Louisiana Universities Marine Consortium and Louisiana State University, predicts a 2012 Gulf dead zone of 6,213 square miles.

“These dead zones are ecological time bombs.”
—U-M aquatic ecologist Donald Scavia

The Michigan forecast model is based solely on 2012 spring nutrient inputs from the Mississippi River, which are significantly lower than average due to drought conditions throughout much of the watershed. The Louisiana State University forecast model takes into account last year's above-normal nutrient load, which the Louisiana researchers say can remain in bottom sediments and can result in a "carryover effect" that increases the size of the 2012 dead zone.

Last year, the Gulf dead zone measured 6,765 square miles. The largest Gulf hypoxic zone measured to date occurred in 2002 and encompassed more than 8,400 square miles. The Gulf dead zone has averaged about 6,000 square miles over the past five years.

This year, for the first time, Scavia's U-M team was able to forecast the volume of hypoxic water contained in the dead zone. The most likely 2012 scenario corresponds to a volume of 2.6 cubic miles, according to the U-M team.

Scavia, director of the Graham Sustainability Institute and special counsel to the U-M president for sustainability, also released his annual Chesapeake Bay dead zone forecast today. It calls for an average-size dead zone in the Bay this year, down significantly from last summer's record-setter.

"These dead zones are ecological time bombs," he said. "Without determined local, regional and national efforts to control nutrient loads, we are putting major fisheries at risk."

In 2009, the dockside value of commercial fisheries in the Gulf of Mexico was $629 million. Nearly 3 million recreational anglers further contributed more than $1 billion to the Gulf economy, taking 22 million fishing trips.

“We should not lose sight of the ongoing need to reduce the flow of nutrients to the Mississippi River and thus the Gulf.”
—NOAA Administrator Jane Lubchenco

Farmland runoff containing fertilizers and livestock waste—some of it from as far away as the Corn Belt—is the main source of the nitrogen and phosphorus that cause the annual Gulf of Mexico hypoxic zone. Each year in late spring and summer, these nutrients flow down the Mississippi River and into the Gulf, fueling explosive algae blooms there.

When the algae die and sink, bottom-dwelling bacteria decompose the organic matter, consuming oxygen in the process. The result is an oxygen-starved region in bottom and near-bottom waters: the dead zone.

"This forecast is a good example of NOAA, USGS and university partnerships delivering ecological forecasts that quantify the linkages between the watershed and the coast," said NOAA Administrator Jane Lubchenco. "While the occurrence of a low-flow year following a year with major flooding will help us to evaluate any carryover effect from prior years, we should not lose sight of the ongoing need to reduce the flow of nutrients to the Mississippi River and thus the Gulf."

According to U.S. Geological Survey estimates, the Mississippi and Atchafalaya rivers transported 58,100 metric tons of nitrogen (in the form of nitrite plus nitrate) to the northern Gulf in May 2012, an amount that is 56 percent lower than average May nitrogen loads estimated in the last 33 years.

"These forecasts are the product of decades of research, monitoring and modeling on how decisions we make in the vast drainage basin of the Mississippi and its tributaries translates into the health of the coastal zone of the Gulf of Mexico," said U.S. Geological Survey Director Marcia McNutt. "Comparing the actual hypoxic zone against the predictions will help scientists better understand the multiyear memory of this complex land-sea system, and ultimately better inform options for improving ecosystem productivity."

About a thousand miles northeast of the Gulf of Mexico in Chesapeake Bay, this year's hypoxic zone is expected to measure about 1.5 cubic miles, Scavia said. That's about average compared to measured volumes since 2000 but much smaller than last year's record-setter of 2.75 cubic miles, which was due to spring storms that washed large amounts of nutrients into rivers that feed the Bay.

So far in 2012, rainfall in the Chesapeake Bay watershed has been 50-to-75 percent of normal, Scavia said.

The actual size of the 2012 Gulf hypoxic zone will be announced following a NOAA-supported monitoring survey led by the Louisiana Universities Marine Consortium between July 27 and Aug. 3.

The amount of nitrogen entering the Gulf of Mexico each spring has increased about 300 percent since the 1960s, mainly due to increased agricultural runoff. The Gulf of Mexico/Mississippi River Watershed Nutrient Task Force has targeted 1,900 square miles as a long-term goal for the size of the Gulf dead zone.

Related Links:
University of Michigan hypoxia forecasts:
http://snre.umich.edu/scavia/hypoxia-forecasts
NOAA hypoxia pages:
www.cop.noaa.gov/gulf_hypoxia_forecast/default.aspx
Louisiana Universities Marine Consortium hypoxia information and forecasts: www.gulfhypoxia.net
U.S. Geological Survey Gulf of Mexico nutrient and stream flow information: http://toxics.usgs.gov/hypoxia/mississippi/oct_jun/index.html


U-M Sustainability fosters a more sustainable world through collaborations across campus and beyond aimed at educating students, generating new knowledge, and minimizing our environmental footprint. Learn more at sustainability.umich.edu

Jim Erickson | EurekAlert!
Further information:
http://www.umich.edu

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>