Oceanographer Steve DiMarco of Texas A&M University, a leading authority on the Gulf of Mexico's "dead zone," and his team of researchers have been awarded $725,467 for the first year of a five-year, $3.72 million project that seeks to better understand and predict where and when the dead zone will happen each year. This new project builds on six prior years of funding.
The Northern Gulf of Mexico Ecosystems and Hypoxia Assessment Program of the National Oceanic and Atmospheric Administration (NOAA) recently announced first-year funding for a new study under DiMarco titled "Mechanisms Controlling Hypoxia: Integrated Causal Modeling," which is expected to continue for the next five years.
Dead zones, or hypoxia, occur when oxygen in water drops below 2 milligrams per liter. Severe hypoxia levels can result in fish kills and adversely affect many types of marine life.
DiMarco and his team have examined dead zones off the Louisiana and Texas coasts to track the size and frequency of these occurrences and, more importantly, identify key factors that contribute to them.
The official size of the dead zone found in 2008 off the coast of Louisiana, as measured by a group of investigators in Louisiana, was 7,988 square miles, the second largest since measurements began in 1985. This represents a land area greater than the state of Massachusetts.
The 2009 dead zone was predicted to be among the largest ever recorded, but actual observations showed it instead to be the fourth smallest on record. The predictions were based largely on the amount of nutrients entering the Gulf via the Mississippi River. The low levels of oxygen in dead zones are caused primarily by nutrient pollution from farm fertilizers and other sources as they empty into rivers and eventually into the Gulf of Mexico.
DiMarco and colleagues have found, however, that other factors such as wind and current reversals, low waves, summer heat and upwelling from coastal marsh
|Contact: Steve DiMarco|
Texas A&M University