Record Dead Zone Possible


A team of scientists from Louisiana is currently bobbing about in the Gulf of Mexico on a research boat gathering data on what has become known as the 'dead zone.' It's a layer of saltwater with such low oxygen levels it can't support marine life. Some computer models predict this season it may become the largest ever measured.

Researchers predict this year the 'dead zone' could measure a record 8,800 square miles, about the size of the state of New Jersey. Scientists have been tracking this summer phenomenon for more than two decades.

It's caused by freshwater rivers flushing organic material and nutrients into the gulf. The freshwater floats on top essentially sealing off the oxygen supply to the lower layers of saltwater. At the same time, the extra nutrients cause algae blooms which eat up the oxygen in lower levels of saltwater.

Dr. Steve DiMarco, an associate professor of oceanography at Texas A&M University, just returned from a four day cruise in the dead zone where he measured water density and oxygen levels.

DiMarco found hypoxia, extremely low levels of oxygen, at nearly all of his 75 measuring stations. He blames spring floods in the lower Mississippi Basin for the intensity and worries because floods from the upper Mississippi have not reached the Gulf.

Joe Murphy, Florida Director of the Gulf Restoration Network, says Floridians should be concerned about the dead zone. He thinks the increased use of fertilizers to produce ethanol grains also is contributing to the size and intensity of the dead zone.

Murphy is working with local governments on Florida's coast to adopt regulations limiting fertilizer and nutrient runoff during the rainy season.

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