Jun
17
2010

The Mississippi is saving coastal Louisiana wetlands

NCED researchers studying delta dynamics in coastal Louisiana
NCED researchers studying delta dynamics in coastal LouisianaCourtesy National Center for Earth-surface Dynamics
The Mississippi River has turned out to be a big, muddy, silent hero in the fight to save Louisiana's wetlands from the oil spill.

It turns out that many scientists believe that the flow of fresh water from the Mississippi River into the Gulf of Mexico has thus far kept the oil slick offshore and out of wetlands.

Guerry Holm, a researcher with the National Center for Earth-surface Dynamics (NCED) tells me that the flow of the Mississippi River has been at a relatively high stage for the past two months and that the river's high volume of freshwater has acted as a hydrologic barrier, keeping oil from moving into the Mississippi Delta wetlands from the sea. Holms is now studying how two river characteristics—the slope of the water surface from the river delta to the sea and the time it takes water to move through a wetland to the sea—help mitigate oil contamination of the wetlands.

Holm is collaborating on the research with NCED Principal Investigator Robert Twilley, who is also busy addressing an immediate concern: the flow of the Mississippi tends to drop seasonally, starting in June. If that happens and Mississippi water flow into the delta decreases, Twilley, Holm, and others worry that oil will reach more of the wetlands sooner.

To address these concerns, some area scientists are proposing to shift the flow of water between the Mississippi and a river in Louisiana it feeds called the Atchafalaya. Twilley supports the idea: "We've been in conversation with U.S. Army Corps of Engineers and the state [of Louisiana] about how to manage the river as a protection system," Twilley reports.

Unfortunately, the river flow adjustments may be difficult to accomplish for political reasons. The diversion structure used to control flow between the Mississippi and Atchafalaya Rivers is controlled by Congress. Earlier proposals to send more water down the Mississippi have been met with resistance.

Your Comments, Thoughts, Questions, Ideas

Shana's picture
Shana says:

This is awesome news. I'm not sure how I feel about altering the river flow, though--but perhaps the benefits would outweigh the risks. That estuary is so vital!

posted on Wed, 06/23/2010 - 12:51pm
Anonymous's picture
Anonymous says:

what is the most common species in the wetlands!?

posted on Fri, 06/25/2010 - 4:52pm
Deborah's picture
Deborah says:

I'm mot sure what is the most common species within the wetlands. I think it depends on how you think about it... there are thousands of bacterial species with trillions (or more) of members within the wetland soils. They do pretty important work in soaking up nitrogen from the water and making nutrients available to plants.

The marshes also serve an important role as a buffer to communities further inland, protecting them from storm surges, a fact that we were all reminded of in the wake of Hurricane Katrina.

posted on Sat, 07/03/2010 - 8:53am

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