Wetlands of Louisiana facts for kids

The wetlands of Louisiana are special areas in southern Louisiana where the land is covered or soaked with water. These places are like a mix of land and water, including swamps, marshes, and areas where rivers meet the sea (estuaries).

The Environmental Protection Agency says wetlands are areas that are often flooded or very wet. They have plants that are specially made to live in wet soil. Different kinds of wetlands form based on things like how much water there is, how rich the soil is, and how salty the water is. For example, around Lake Pontchartrain, you can find different wetlands like cypress swamps and freshwater marshes.

Louisiana has a huge amount of wetlands, about 40 to 45 percent of all wetlands in the lower United States. This is because the Mississippi River flows through Louisiana on its way to the Gulf of Mexico. The river brings water from many states, making Louisiana a "drainage gateway" for a very large area. This makes Louisiana's wetlands super important for the whole country.

On the eastern side of Louisiana, wetlands blend into pine forests. These forests are home to rare plants like pitcher plants and animals like gopher tortoises. The western side has wet prairies, which used to be huge but are now mostly gone. The eastern coast of Louisiana is more likely to wash away because it was built up by silt (mud and sand) from the Mississippi River. However, large walls called levees now stop the river from bringing new silt to these areas. This means the land can sink without new dirt to build it up.

Because of this, and because sea levels are rising due to global warming, the eastern coast might turn into open water. The western coast might not be affected as much because its marshes don't go as far inland.

To protect these important areas, the National Oceanic and Atmospheric Administration (NOAA) created programs like the Coastal Zone Management Act. These programs help Louisiana plan how to save its coastal lands. In 2008, Louisiana also created the Coastal Protection and Restoration Authority (CPRA) to make a "Master Plan" for protecting and restoring its coast.

Louisiana's Coastal Wetlands

The coastal area of Louisiana stretches from the border of Texas to the Mississippi state line. It has two main wetland systems: the Deltaic Plain (where the Mississippi River built up land) and the Chenier Plain. The Deltaic Plain has many barrier islands, like the Chandeleur Islands. Programs like the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) have spent a lot of money to fix damaged wetlands and barrier islands.

Why Wetlands Are Disappearing

Diorama showing how human activities cause wetland loss in coastal Louisiana.

For a long time, many people didn't understand how important wetlands were. Wetlands do many helpful things: they control floods, provide homes for fish, store carbon, and filter water. Today, experts agree that two main reasons for wetland loss are the land sinking (called subsidence) and saltwater getting into freshwater areas. This saltwater often comes from canals dug for oil and gas work.

Let's look at some of the reasons why Louisiana's wetlands are shrinking:

Land Sinking (Subsidence)

The land in Louisiana is definitely sinking. Some people think this happens because oil and gas are pumped out from underground. When billions of barrels of oil and gas are removed, the ground above them can slowly collapse, causing the land to sink. Others believe that sinking is a natural process in river deltas as the soil settles. They argue the real problem is that the Mississippi River no longer brings new sediment (dirt) to build up the land. Rising sea levels, about 2 millimeters per year, also make the problem worse.

Soil Compacting

The soil in Louisiana's wetlands is often made of soft, organic material (like peat). This soil can compact, or squeeze together, by 5 to 10 millimeters or more each year. This compaction also causes the land to sink. When planning restoration projects, scientists must consider how much the ground will compact.

Levees and Dams

Large walls called levees and dams have been built along the Mississippi River. These levees stop the river from flooding, which is good for towns, but bad for wetlands. The floods used to bring new sediment (dirt and mud) to the marshes, helping them build up. Now, this sediment flows straight into the Gulf of Mexico. Without new dirt, and with the land sinking, the wetlands slowly turn into open water. Since 1930, Louisiana has lost over 1,900 square miles (4,900 km²) of land. This is like losing an area the size of a football field every 30 minutes! To fix this, some levees might need to be removed so the river can bring sediment back to the wetlands.

Logging Cypress Forests

In the early 1900s, many large cypress forests in the wetlands were cut down. Loggers often built canals to move the trees. After logging, these canals allowed salty ocean water to flow into freshwater wetlands. This saltwater stopped new cypress trees from growing back.

Nutria (Rodents)

Another problem is the nutria, a large rodent from South America. They were brought to Louisiana in the 1930s, and now there are millions! Nutria eat wetland plants, which causes the land to lose vegetation. Even worse, they eat the dead plant matter that would normally build up as peat, which helps raise the marsh level. Large alligators are natural predators of nutria and might help control their numbers.

Why Wetlands Matter

The disappearing wetlands in southern Louisiana affect many things, from culture to the economy.

• Fishing: Commercial fishing in Louisiana is a huge business, worth over $300 million. More than 70% of this comes from animals like shrimp, oysters, and blue crabs, which use the coastal wetlands as nurseries for their young.
• Recreation: Many people enjoy hunting and fishing in the wetlands. Other fun activities include boating, swimming, camping, hiking, bird watching, and photography.
• Nature's Filters: Wetland plants, like bald cypress trees and dwarf palmetto, act like natural filters. They help clean polluted water by removing heavy metals, sewage, and pesticides before the water reaches the Gulf of Mexico.
• Wildlife Home: Wetlands are home to many animals, including osprey, anhinga, ibis, herons, egrets, manatees, alligators, and beavers.

Even though some natural things affect wetlands, many people believe that human actions have caused most of the decline. Before levees were built, floods would bring new sediment to the wetlands, balancing out the land sinking. But now, the sediment goes into the Gulf. This, along with rising sea levels and canals, has caused the wetlands to shrink. This also means less protection from strong storms like Hurricane Katrina. Groups like the Lake Pontchartrain Basin Foundation are working on plans to restore river habitats and cypress swamps, which could be a model for other coastal areas.

Oil Company Canals

For a long time, people have thought that the canals dug by oil companies to access drilling sites cause coastal land to wash away. These concerns were first brought up in 1925 and led to lawsuits against oil companies in 2013.

Images for kids

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  The Atchafalaya Basin is a large wetland and swamp in Louisiana.

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  A diorama showing how human activities cause wetland loss in coastal Louisiana.