Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers confirm dead zone off Texas coast since 1985

04.04.2008
Researchers at Texas A&M University have confirmed for the first time that a “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 in the area.

Steve DiMarco, associate professor in Texas A&M’s College of Geosciences who has studied dead zones in the Gulf of Mexico for more than 15 years, believes the dead zone area off the Texas coast extends from the Texas-Louisiana border area to Brownsville. 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.

“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 extremely low.”

DiMarco recently presented his findings to the 2008 Ocean Sciences Meeting in Orlando, Fla.

DiMarco examined water samples – provided by Texas Parks and Wildlife, NOAA (National Oceanic and Atmospheric Administration) and other groups – from the area taken since 1985 and found that, with few exceptions, dead zone areas have occurred almost every year since that time.

Key areas sampled included Sabine Pass, Matagorda Ship Channel, Galveston-Boliver Pass, 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.

“The low oxygen levels since 1985 are frequent and persistent,” he noted.

“It proves that a dead zone occurrence is not a one-year or two-year event, but it has happened just about every year for at least the last 23 years.”

Previous dead zones have been recorded off the Louisiana coast for years, near the Mississippi delta region, and a dead zone there has been measured at more than 7,900 square miles, or about the size of Delaware and Connecticut combined.

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.

“The new results show that another ‘fingerprint’ from Texas is the cause of dead zones since 1985,” he adds.

“Hypoxia – oxygen-depleted water – occurs when the oxygen levels fall below 2 milligrams per liter, but we found numerous samples that were even one-half of that, meaning severe hypoxia has occurred.”

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 Texas coast.”

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 several sites.

Keith Randall | EurekAlert!
Further information:
http://www.tamu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>