Why is the land disappearing?
Hey, thanks for asking! (o:
The land it sinking because the Mississippi has been beaten into submission, pretty much. It naturally wants to go it's own way, which would allow it to deposit rich sediment into the wetlands of southern Louisiana, sediment from Canada and everywhere in between. That would create new land. The Army Corps has spent untold billions leveeing that river into submission, which has saved cities from flooding so that's a good thing. But in the meantime, the southern coast is dying.
This area is so important. Birds flying south for the winter, and flying back north after, all migrate here. If these wetlands keep sinking, and killing the plant life because salt water is poisoning their environment, I guess they will have to find another "meeting place." Also, 30% of the nation's seafood comes from the area, and if the land keeps sinking, the shrimpers, crappers, etc. will eventually have to move away. Their homes are literally going to float away.
One of the book's 'characters' makes the statement that in a few hunderd years, Baton Rouge will a coastal city.
Anyway, it's a very good read. I feel like I know these people now! The author immersed himself into the Cajun and Houma Indian cultures and it's truly an amazing life they live.
To elaborate on the poster's response a bit further, all of southern Louisiana is deltaic deposits thousands of feet thick. Historically, the Mississippi has drifted back and forth in a broad fan. These sediments are still consolidating and the underlying crust is slowly being depressed as well. So there is a steady sinking of the land.
However, before levees were built, that in turn was offset by the deposition of additional sediments. During floods, floodwaters spill out in a broad swath and drop their sediment loads over the land. Floods over the centuries gradually pushed the coastline out and kept the land above sea level, while also bringing in fresh nutrients.
Now, with the levees, the waters go straight out into the Gulf without a chance to drop sediments and compensate for the gradual settling. Plus, canals have been dredged which speeds up the inflow of salt water. So the swamps and marshes are gradualling sinking.
The land is disappearing partly because of the loss of alluvial buildup after many decades of having a massive levee system. It is also disappearing largely because of subsidence. Enormous quantities of oil, gas and minerals have been removed from the ground. This is complicated by the fact that the marshes are crisscrossed by manmade canals. To understand subsidence, stick a soda straw into a glass of liquid. Suck. What you have in your mouth comes from the bottom of the glass and the surface level sinks. That is exactly what is happening to the land in South Louisiana. Eventually, the Gulf of Mexico will cover much of South Louisiana.
The term joie de vivre -- joy in living -- could have been invented to describe the Acadian/Cajuns. They do more with less than almost any other people. Their culture is one of the most interesting and valuable aspects of Louisiana and is well worth preserving.