Four exotic species in one photograph can totally clog up and change a habitat for the worst. Pictured: water hyacinth, alligator weed, elephant ear, and tallow trees.

The United States is filled with plant and animal species that do not naturally occur here. Camellias are beautiful flowers that many people in Louisiana grow and enjoy. These non-native or exotic plants cause no harm to the natural ecosystem. Some exotic species that are introduced into a habitat become invaders. An exotic invasive species is bad news to any habitat!

Louisiana has some foreign invaders that are changing wetland ecosystems and upsetting the natural balance in many areas. CC and I are seeing this everyday as springtime is a growing time for many of the marsh invaders. An ecosystem is a fragile thing and if something enters a system that can eat, destroy, or crowd out the native species you have big problems.

Some of the invasive species we are seeing on marshmission are nutria, water hyacinths, hydrilla, salvinia, Chinese tallow trees, and zebra mussels. These invaders were introduced to Louisiana in many different ways and they are causing many different types of damage.

 
Let’s look at some of the problem invaders of our wetlands.

FAST FACTS ON ALIEN INVADERS

WATER HYACINTH: CC calls this invading plant “Devil in Disguise.” It is a lovely flowering water plant that was introduced in Louisiana in the 1884 World Industrial Cotton Exposition in New Orleans. Visitors to the Japanese exhibit were given a hyacinth as a gift. Many “gifts” were put in local ponds and waterways and quickly spread. Quickly is the key word as these plants can double their population in 2 weeks clogging up bayous and waterways. Many times CC and I have had to walk our canoe over huge floating patches of water hyacinth. The thick patches also cut off the sunlight to the plants and animals below the water’s surface killing them. The beauty of the water hyacinth really is a disguise!

NUTRIA: Annie wrote about the “naughty nutria” in volume 7 of the Coastal Classroom.    Archive back to Annie’s column and read about this invader of the marsh!

SALVINIA: This tiny water fern floats. You may have bought some to decorate your fish aquarium or outdoor pond. When released, this plant reproduces rapidly and clogs canals and bayous. Salvinia also takes over native species such as duck weed which is a very important food source for many water birds.

HYDRILLA: Another invasive water plant used in aquariums that grows thickly under water. It takes over waterways and can really ruin the motor of your boat.

CHINESE TALLOW TREES: This ornamental tree came to the United States from China in 1776 by Ben Franklin. The seed of this tree was used to make wax for candles and soap. Tallows were planted in the Gulf States to start a soap industry. Today people plant them because they are pretty. In the wild, this tree easily adapts to different habitats and takes over as the dominant plant. When mature this tree produces 100,000 seeds per year!

ZEBRA MUSSELS: This tiny invader is a freshwater bivalve that came to the U.S. in water discharged from large ships. It is native to the Soviet Union and has spread through the country. The waters of the Mississippi have carried this mussel to our region and it is a real nuisance. It competes with our native mussels and wins! Zebra mussels also ruins water filtration systems and water intake pipes by attaching to them.

Lots of time and money is spent to stop the spread of these and other invading species. Once a truly invasive species is introduced it is almost impossible to control. Be careful with what you release into lakes or ponds, you never know what can become an invader!  

Baby black bear attempting to climb tree.

“Lions and Tigers and Bears, OH MY!”  I have met Mike the Tiger at LSU and I have seen lions at the zoo, but these two creatures are non-native species to Louisiana. Bears, on the other hand, are native to Louisiana!