A juvenile apple snail found in City Park
Southeast Louisiana certainly has its fair share of invasive species. Our warm climate, lush vegetation, and plentiful water make a perfect habitat for a number of non-native species.
Not every non-native species is invasive. For example, some trees in Couturie Arboretum are not native to Louisiana. However, because they don’t outcompete our native trees for resources, they are not considered invasive.
Invasive species in our state include both plants and animals. Chinese tallow, water hyacinth, and salvinia are just a few of the many invasive plants. When it comes to animals, we’ve got fire ants, nutria, feral hogs, and today’s main character: the apple snail.
About the Apple Snail
Apple snails are freshwater snails known for their large size and attractive shells. They also have both gills and lungs, which means they can breathe underwater and above water.
Originally from South America, apple snails are often kept as aquarium pets in the US. This is most likely how they were introduced to Louisiana and became an invasive species.
Apple snails were never seen in Louisiana’s waterways until 2006 near Gretna. It’s believed that pet apple snails were released in a drainage basin around that time. Eventually, the fast-reproducing snails’ population expanded throughout our waterway system.
Spotting Apple Snails
While canoeing or kayaking on the water, many people can easily spot apple snail egg clusters. These bright pink, bumpy smears on surfaces above the water indicate that apple snails are present and reproducing.
Apple snail eggs are often found attached to hard surfaces along waterways like canals, ditches, and bayous.
Many of our visitors to LOOP NOLA have also found apple snail shells in and around Couturie Arboretum. These shells are often discarded on the ground near water by raccoons that have captured the snails and eaten them.
The shells are large, often the size of a child’s hand. However, it’s important not to touch the shells unless you’re wearing gloves or are able to wash your hands immediately afterward. That’s because apple snails can carry a parasite known as rat lungworm.
This parasite normally affects animals that eat apple snails, but can also affect humans who touch their shells. If you touch an apple snail shell, be sure to wash your hands as soon as you can.
Dangers to the Ecosystem
In addition to carrying dangerous parasites, apple snails pose problems for our local ecosystem. The apple snails are bigger than our local snails, so eat much more food. They also reproduce at a faster rate than our local snails.
The result of this is that apple snails outcompete our local snails and replace them over time. Meanwhile, animals that normally rely on our small local snails for food may not be able to eat the large apple snails. Those animal populations are then also impacted by the apple snail.
What can we do?
Right now, the best way to fight against apple snails is to destroy their bright pink egg clusters. By knocking them into the water where they can’t hatch or crushing the clusters, we can prevent even more apple snails from taking over our waterways.
