Featured Research

from universities, journals, and other organizations

'Dead Zone' Area Shrinking, Texas A&M Prof Says

Date:
September 30, 2004
Source:
Texas A&M University
Summary:
A team of Texas A&M University and Louisiana State University scientists conducted a research cruise in late August to the "dead zone" - a region in the northern Gulf of Mexico that suffers from low oxygen and results in huge marine losses - and much to their surprise, the "dead zone" area had either moved or had disappeared completely.

COLLEGE STATION, September 30, 2004 - A team of Texas A&M University and Louisiana State University scientists conducted a research cruise in late August to the "dead zone" - a region in the northern Gulf of Mexico that suffers from low oxygen and results in huge marine losses - and much to their surprise, the "dead zone" area had either moved or had disappeared completely.

Steven DiMarco, associate professor in the Department of Oceanography and leader of the team, found that some areas that were previously hypoxic - a technical term for extremely low dissolved oxygen concentrations in water - had broken up and appeared to pose little threat to marine life, while in other areas the hypoxia appeared to have moved further off shore.

Hypoxia can result in fish kills and can adversely affect many types of marine life where it is present. The dead zone area encompassed more than 6,000 square miles this year.

"We found that the hypoxia had moved offshore from shallow waters to much deeper waters in the Gulf," DiMarco explains. "In other words, much of the dead zone had broken up, and this very much surprised us."

DiMarco believes there are two reasons why the region affected by hypoxia broke up and changed location.

"Strong coastal currents can develop and breakup the stratification that causes hypoxia," he says. "Another is offshore circulation features, such as eddies, that intrude onto the continental shelf. We think this could break down the hypoxia in the area as well."

The NOAA (National Oceanic and Atmospheric Administration) study, conducted from Texas A&M's research ship R/V Gyre, stretched from an area near Southwest Pass, La., to the Calcasieu Ship Channel near the Texas-Louisiana border.

There are numerous theories as to the cause of the dead zone. Many scientists believe it is caused by fertilizer runoff from the Mississippi River, while other theories point to more complicated and interrelated factors.

"Just a few weeks before we went on our research cruise, other teams in the area reported seeing few if any fishing boats in the dead zone area," DiMarco says.

"But we were surprised to see a lot of fishing boats, especially shrimp boats, there. That means marine life has returned to the area where just three weeks before, the oxygen levels were recorded as being extremely low.

The dead zone has been studied and tracked since it was discovered 20 years ago, DiMarco says.

"We need to do some further research to determine the specific mechanisms under which hypoxia is created, maintained, and ultimately dissipated," he believes.

DiMarco will present his findings next month at a meeting of the International Marine Environmental Modeling Seminar in Washington, D.C.


Story Source:

The above story is based on materials provided by Texas A&M University. Note: Materials may be edited for content and length.


Cite This Page:

Share This




More Earth & Climate News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Climate Change Could Cost Billions According To White House

Climate Change Could Cost Billions According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins