July 2008

U.S. Water News Online

CHAUVIN, La. — The head of the Louisiana Universities Marine Consortium will receive $50,000 and a gold medal for her research about the dead zone that forms every summer in the Gulf of Mexico.

The 2008 Athalie Richardson Irvine Clarke Prize, which the National Water Research Institute presents in Huntington Beach, Calif., is the latest of many honors for the work Nancy Rabalais has been doing since 1985.

Last month, the American Society for Limnology and Oceanography gave her the Ruth Patrick Award for aquatic scientists who make substantial strides toward solving important environmental problems.

The Clarke Prize money will go right back to the marine consortium, Rabalais said. "I can use it for things that my grants might not cover, like student travel to meetings or travel to meetings not covered by a grant, or special equipment."

The water research institute established the prize in 1993 to recognize excellence in water-science research and technology.

Its citation said Rabalais has dedicated her career to understanding and reducing water quality changes caused by people — particularly the long-term effects of excess nutrients and petroleum on marine ecosystems.

She began mapping and studying the dead zone shortly after she came to LUMCON in 1985. That project, initially made up of Rabalais and two scientists at Louisiana State University, now involves about 15 people at LUMCON and LSU. LUMCON itself has grown from about 25 to about 65 people over the same period, Rabalais said.

"We didn't really know what we were going to find. It became obvious after a while that it was a significant issue — that it not only affected the Gulf of Mexico but the whole Mississippi watershed," she said.

Her team found that fertilizer runoff into the Mississippi River and its many tributaries is a major cause of the oxygen-poor area.

The fertilizer feeds a growth spurt of algae and microorganisms. Those die and fall to the bottom, where their decay consumes oxygen. From the bottom up, oxygen disappears. The water becomes hypoxic — very little oxygen — then anoxic, meaning no oxygen.

Researchers believe that this year's dead zone may be the largest and most severe ever — and some expected that even before spring floods carried more runoff than usual into the river.

The algae bloom started in February and low oxygen readings began in March, both a month earlier than usual, Rabalais said.

The floods also prompted the Army Corps of Engineers to open the Bonnet Carre Spillway, diverting river water into Lake Pontchartrain. The dead zone is generally west of the Mississippi River. But nutrient-laden fresh water coming out of the lake may contribute to low oxygen in the Chandeleur Sound and other areas east of the river, Rabalais said.