This week, Alexandra Cousteau and the Expedition Blue Planet crew talk to musician and “voice of the wetlands,” Tab Benoit. Tragically, Louisiana’s wetlands are disappearing—and disappearing fast. So fast, in fact, that if you buy a map of the coastline of Louisiana, it’ll be no good just five years from now.

Why save the wetlands?

These wetlands serve as more than a relaxing place to hunt, fish, and birdwatch. They also filter harmful chemicals out of the water, work like speed bumps for hurricanes, and play a critical role in supporting the land structure of all New Orleans. Without them, and with the compounding effects of climate change causing sea levels to rise, New Orleans might very well sink or be blown away into oblivion. If land loss continues at the current rate of 34 square miles per year, Louisiana will shrink another 700 square miles by 2060.

What’s behind the disappearing wetlands?

Channels, levees, locks and dams separate over 90 percent of the Mississippi River south of St Louis all the way to New Orleans from its floodplains. People have been busy constructing such water management devices since the French first settled the region in 1720. But they interfere with the delta’s natural regulation of water flow: three miles of wetlands can reduce water storm surge height by a foot. In addition, jetties extend far out into the Gulf of Mexico to ensure a channel wide and deep enough for barges to travel up the Mississippi River. But these same jetties carry sediments out to sea that otherwise would be forming new land to help offset the loss of old land.