Zebra MusselsToday, I continue my coverage of a few invasive species commonly found in your local waters. In Part One, I outlined the aquatic plant species known as the water hyacinth, which spreads like wildfire and chokes out oxygen, blocks sunlight, and forces many other species away from wherever the plant is allowed to thrive. There is another invasive species, however, that has made a name for itself over the last twenty years, and continues to plague our waters: the zebra mussel.

The zebra mussel is a small mussel species that gets its name from the striped pattern on its shell. Native to eastern Europe, where several water fowl species eat them, the mussels arrived in the Great Lakes after attaching to foreign ships and have become quite a nuisance since their discovery here in 1988. The mussels have a rapid growth rate (an adult female can produce 30,000-100,000 eggs each year, which mature within a year) and have been found as far east as New England. They are so effective at infesting new areas due to their free-swimming larvae, which, within two to three weeks, attaches itself to anything from boats to rocks, and even other mussels.

Like several other organisms, zebra mussels feed on small plankton. The problem, however, is that zebra mussels are such voracious feeders that they consume so much plankton that other species can’t feed themselves. This eventually starves any native species and completely depletes the supply of the plankton in a given body of water.

While my main focus in an article such as this is the effect that a foreign species has on the native ecosystem which it infests, zebra mussels wreak absolute, unrelenting havoc on many man-made creations. The mussels often accumulate and clog intake systems of water treatment plants, industrial facilities, power generating locations, irrigation systems, and boa engines. Furthermore, the zebra mussels also pose a potential threat to humans. Their feeding habits enable them to produce waste materials in the form of harmful pollutants. When ingested by other species, the pollutants then move up the food chain, contaminating each species along the way. The zebra mussel is also well-known for its razor-sharp shell, which can badly cut your feet if you’re not wearing water shoes.

There have been steps taken throughout the years to quell and hopefully stop the spread of zebra mussels. In Europe, for example, where zebra mussels have thrived for years, many affected facilities employ the use of two, separate pipes. When one pipe is clogged with a colony of mussels, they shut it down and utilize the spare pip while the effected one is cleaned. Also, regions where the mussel has newly been discovered, wildlife organizations are working tirelessly to educate boaters and outdoor enthusiasts on the mussel, and ways they can prevent its spread.

The zebra mussel is a difficult species to contain, as its spread is passive and nearly unstoppable. Its larvae are so small and quick to attach to an object—mainly boat hulls—that the species seems to be somewhat of an aquatic plague. If you’ve ever visited the waters where zebra mussels have staked their claim, then you’ve no doubt seen the damage they can cause to both the ecosystem and nearby structures. The best way for boaters to help prevent it from spreading further is to clean your hull thoroughly after a day on the water, as well as your livewell. Not only does every little bit help, but if we can suppress the spread of zebra mussels, then we won’t all have to buy water shoes just to go swimming.