The oxygen-starved "cloud" — hypoxia explosion, or dead zone
— at the bottom of the mighty Mississip' was nearly 8,000
square miles last summer, about the size of New Jersey.
Off the Texas coast, we are now being informed by researchers at Texas
A&M, is a coast-long lifeless stretch of water that has been sitting undetected for decades.
And it's not likely to dissipate anytime soon.
This information comes less than a year after a portion of this massive
zone was first confirmed off the Texas coast. Researchers say the zone
extends at least 20 miles south of our sands and is "patchy," though
Says Steve DiMarco, associate professor in Texas
A&M's College of Geosciences:
"Not all of the area from
the Texas-Louisiana coast to Brownsville is a dead zone area, but very
much of it is," DiMarco explains. "The Texas dead zone appears to be
more patchy and not as continuous as the Louisiana dead zone to the
east, but much of the region there has very low oxygen levels, some
Dead zones are caused by farm fertilizers, urban runoff, and poorly
operating water treatment plants that send huge nitrogen and phosphorus
loads into the Gulf, where they cause algal blooms that literally eat
up much of the available oxygen, leaving the affected waters at less
than 2 parts per million dissolved oxygen, making it impossible for
aquatic life to survive.
DiMarco says a comparison
would be that of standing on top of a mountain. "You know the air is
going to be thin up there because of the altitude," he says. "The thin
air has low oxygen levels making it uncomfortable and sometimes deadly
to humans. That's similar to what happens to marine organisms along the
He notes the dead zone is believed to extend about 20 miles off the
coast in these areas, but could be larger. "That's one big question we
need to find out – how large an area is being affected by
this dead zone?" he says.
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
What can be done to stop
the dead zone in Texas?
[Below text and dead zone images courtesy of Carleton
What Can be Done to Remediate the Problem?
The key to minimizing the Gulf dead zone is to address it at
the source. Solutions include:
Using fewer fertilizers and adjusting the timing of
fertilizer applications to limit runoff of excess nutrients from
Control of animal wastes so that they are not allowed to
enter into waterways
Monitoring of septic systems and sewage treatment
facilities to reduce discharge of nutrients to surface water and
Careful industrial practices such as limiting the discharge
of nutrients, organic matter, and chemicals from manufacturing
These solutions are relatively simple to implement and would
significantly reduce the input of nitrogen and phosphorus to the Gulf
of Mexico. A similar approach has been used successfully in the Great
Lakes' recovery from eutrophication.
The government is also funding efforts to restore wetlands
along the Gulf coast to naturally filter the water before it enters the