Hint: They aren't good.
zebra mussels close up
Credit: Star Tribune via Getty Images / Contributor/Getty Images

There's no denying that zebra mussels are a pest. The tiny bivalves, which take their name from the dark, zebra-like stripes on each shell, most likely arrived in the South on freighters that set sail from Eastern Europe. The boats hit the Great Lakes and once on the shores of the United States, the zebra mussels quickly took to their new home, spreading through most major river systems, including traveling down the Mississippi and across the southern region. The invasive freshwater mollusk has set up posts in Texas, North Carolina, and Louisiana and the threat of their invasion has been making headlines in Florida since at least 1991.

The reason their arrival is heralded with such alarm is because they are tenacious and determined. Zebra mussels are small (about the size of a dime), and reproduce quickly, putting rabbits to shame. According to the website Texas Invasives, one zebra mussel can produce up to one million microscopic larvae, which lets them take over a local watering hole really quickly.

Once the population is established, they eat everything, crowding out native clam and mussel species, taking food from local fish, clinging to almost anything in water, and making the water smell and taste foul. They are so good at clumping together that they can take over pipelines, cutting off the pipes that provide water to thousands of homes and businesses. According to the United States Geological Survey, power plants spend millions of dollars removing zebra mussels from clogged water intakes. Zebra mussels are quite fond of making boats and docks their home, too, quickly encrusting hulls and docks with mussels that are both damaging and difficult to clean.

zebra mussels attached to rock
Credit: Fort Worth Star-Telegram / Contributor/ Getty Images

It's not just the South that is being invaded by the pesky bivalves. Zebra mussels have taken over waterways from Canada to Mexico and almost every state in between. Getting rid of them is no easy feat. According to the National Park Service, once a population of zebra mussels has established itself in a body of water, there is very little to be done to remove them. That's why preventing the spread of zebra mussels is the best way to stop them from taking over every lake and river.

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Don't catch or carry zebra mussels even if you want to use them as bait, for food, or keep in an aquarium as a very boring pet. If you own a boat, the National Park Service recommends thoroughly draining boats and motors before leaving a lake or river and washing boats and trailers thoroughly. If possible, let the boat dry for at least five days (the amount of time a zebra mussel can survive out of water) before taking the boat out again. While that sounds like a drag, keep in mind that Texas lakes were free from zebra mussels until about 2009 when they started to take over. Biologists believe the invasion may have started when someone took a spin on a boat that was not properly cleaned. Now, local news outlet KSAT reports that zebra mussels have taken over 17 Texas lakes, and the invasion is costing taxpayers as they work to keep their lakes clean and pipes working properly.