Gulf Coast ‘dead zone’ growing, researchers say

By Greg Barr
Houston Business Journal, April 2, 2008

Texas A&M University researchers have confirmed that a still-growing "dead zone" in the Gulf of Mexico extends along the entire length of the Texas Gulf Coast.
A dead zone occurs when there is hypoxia, or oxygen-depleted water. Such low levels of oxygen are believed to be caused by pollution from farm fertilizers as they empty into rivers and eventually the Gulf, or by soil erosion or discharge from sewage treatment plants.
Researchers suggest that the dead zone has existed off the Texas coast for at least the past 23 years and will likely remain there, causing potential harmful effects to marine life.
Steve DiMarco, associate professor in Texas A&M’s College of Geosciences, believes the dead zone area off the Texas coast extends from the Texas-Louisiana border area to Brownsville, and extends out as far as 20 miles in some areas.
"Not all of the area from the Texas-Louisiana coast to Brownsville is a dead zone area, but very much of it is," said DiMarco, who presented his findings to the 2008 Ocean Sciences Meeting in Orlando, Fla.
DiMarco examined water samples taken from the area since 1985. Areas sampled included Sabine Pass, Matagorda Ship Channel, Galveston-Bolivar Peninsula, Aransas Pass and Brazos-Santiago (Brownsville) Pass.
Water samples contained low oxygen levels, and in some years, alarmingly low, DiMarco said. When a dead zone occurs, marine life can be severely threatened, especially commercial fishing areas.
DiMarco was the first to discover a Texas-created dead zone area off the Texas coast last summer, a result of unusually heavy rains that poured water into the Brazos River. Where the water emptied into the Gulf off the Texas coast, it created the first proven dead zone area that originated from Texas rivers.
DiMarco plans to go to the affected areas off the Texas coast in July for more samples and to test the concentration levels of hypoxia from several sites.