Russia. The land of Sputnik, Dostoevsky, vodka, and….zebra mussels.
Zebra mussels are fingernail-sized, freshwater mussels, native to the lakes in southern Russia. They are named for the striped patterns typically, though not universally, seen on their shells, and are, unfortunately, almost always seen as a menace.
People who have actually heard of zebra mussels typically live near a lake that has been invaded by them. Thus, these people tend to view them very nagatively. To be fair, it is perhaps because the infestation blocked off the pipes to the town’s water tower, or perhaps because someone was enjoying a nice dip in the lake and sliced her foot open on one of the mussel’s sharp-edged shells. They have certainly caused some major problems for the water supply and swimming beaches of Council Grove and Camp White, the stars of my last post.
Basically, I have never heard anyone speak positively of zebra mussels, so my goal today is to change that.
Zebra mussels made it to the US in 1988 when they were brought into the Great Lakes. They travel by attaching to boats, anchors, and chains, or by slipping into a boat’s ballast water. Then they just go where the boat goes, and drop off wherever they choose. Zebra mussels have an incredible ability to survive out of water for days at a time as long as the temperature in low and the humidity is high.
Once zebra mussels find a nice, new home, they start doing as animals do, and begin reproducing – very rapidly. Adult females can produce over 1,000 eggs in each reproductive cycle. That’s over 1 million eggs in a single year. They start these cycles less than two months after they settle into a location. This means that once people realize that there is an infestation, it is already way too late.
Aiding in their survival rate is the fact that zebra mussels have very few predators. In fact, many of the animals (mostly birds) who like to snack on zebra mussels are native to Europe and do not live in North America. Crayfish can eat a substantial number of zebra mussels – about 105 in a single day – but with the reproductive rate being so high, it is hard for any single crayfish to make a significant dent in the mussel population.
Looking at zebra mussels in a purely objective manner, they are super cool creatures. They stowaway on boats, sneak into other countries – continents, even – and then start having babies in the thousands like it’s nobody’s business, because they have virtually no predators. Once they land, they prevent entire populations of people from getting fresh water, and they slice up anyone who tries to touch them. They also reproduce quickly enough to smother other mussel species and prevent them from moving and reproducing, until they eventually die off, leaving zebra mussels to rule all. Remember, these guys are generally no bigger than a dime.
That is amazing. See, the story of the zebra mussel and any opinion of them are all about perspective.
Before closing, I want also to talk about the good things zebra mussels do, not just the awesomely tyrannical things.
Zebra mussels are filter feeders. A single tiny mussel can filter up to a gallon of water every day. Get thousands of these guys filtering, and you have a great way to clean up a lake. After zebra mussels invaded Lake Erie in the 1980s, the water clarity went from 6-10 feet to 10-17 feet.
As the mussels filter the water, sunlight reaches greater depths, allowing different types of algae to grow, which provides new food for the lake inhabitants. In Lake Ontario, the clearer water is preventing bottom shrimp from hiding in the murkiness. The shrimp’s main predator, a type of fish called the alewife, benefits from this, leading to happy salmon who hunt the fattened alewife, which then leads to an exceptionally healthier salmon population. This could potentially lead to a food chain collapse, but right now, Lake Ontario is a great place to be for everyone (except the shrimp…).
It is fascinating to see how different populations react and adapt to one another, how populations shift and move, and how just as one animal joins the food chain, another is bumped off.
So what do you think? I think it’s totally possible to see zebra mussels in a positive light — or at least as super stowaway killers, which is maybe more fun, anyway.