The iconic Mississippi River Delta is of enormous importance to the country, especially near the Gulf Coast.

More than 2 million people live near that part of the Delta.

It's an economic engine home to tourism, fisheries, and a shipping gateway to North America.

And it's also a key wildlife habitat.

Nearly 40% of the coastal wetlands in the contiguous U.S. is found in the

Delta in Louisiana. But it's shrinking considerably due to a number of factors, including

engineering done some decades ago. Our science correspondent, Miles O'Brien, looks at those

problems and efforts to prevent further loss.

All right, ladies, let's get ready for our coring.

In the place where the Mississippi River drains into the Gulf,

we don't actually know what we're going to get here.

Scientists are waist deep.

Here we go. In a desperate effort to stop the largest wetland system in the U.S. from vanishing.

All right, do us the honors.

Great job.

25 to 27.

Great.

Sedimentologist Carol Wilson is an associate professor at Louisiana State University.

I've been doing it for 25 years of my life now.

Yeah, more than half of my life I've been down here playing in the mud.

She and her team are studying the mud in the place they call the bird's foot,

so named because of the way the Mississippi River spreads out into three channels at its mouth.

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