Quagga Mussel: Scourge of the Great Lakes

Back in the 1990s, Bill Clinton was president, alternative music was all the rage, and the Zebra was the mussel du jour of the Great Lakes. In the mussel community, it’s quite gauche to tear apart the native ecosystem one small link at a time over the span of several years. Circa 1988, Zebras stormed in like an unwanted relative at Christmastime and proceeded to mooch off the local food chain, making sustenance scarce for larger predatory animals. They clogged water intakes, encouraged toxic algae blooms, fouled up beaches, and generally acted like a bunch of aquatic jerks across the Great Lakes.

But now it’s the second decade of the new millenium. After 20 years with these ecological scofflaws, you’d think scientists would have found a way to eradicate them. You’d be wrong, because the Zebra has given way to its first cousin, Dreissena rostriformis bugensis, otherwise known as the Quagga. If the Zebra was a petty two-block hustler, think of the Quagga as a mafia Don.

The Quagga hail from the Dnieper, a river originating in Russia and winding through the Ukraine. It’s found primarily within the Dnieper drainage into the Black Sea, which explains how they stowed away on freighters bound for the West. From there, these juiced-up dreissenids found a home in the aforementioned Great Lakes and St. Lawrence Seaway.

Zebra mussels prefer warmer temperatures and, consequently, higher elevations within a given body of water. Quagga, on the other hand, seek out colder temperatures, which means they burrow deeper beneath the lake bed, proving significantly more difficult to remove. Warm temperatures are Quagga kryptonite, however: they seldom survive temps above 32-35 degrees Celsius. Thankfully, this is one of the biggest reasons Quagga have not been found in abundance outside of the Great Lakes.

The havoc they wreak within the Lakes is startling and fast-moving. The Zebra may have been the hare in the race against the tortoise, but now the Quagga is proving that slow and steady indeed wins the race. These mussels have “muscled” out Zebras to the point that Quagga are projected to soon be the dominant dreissenids within the Great Lakes. In fact, Quagga have become so dominant they already own the eastern portion of Lake Erie and the western portion of Lake Ontario. They are now the king of the mussels in these parts and are projected to establish their kingdom across the whole of the Lakes at an alarming rate.

What does this mean for you, the nature lover? It means foul-smelling lakes. It means a dying off of fish from the lack of food sources. It means fish so loaded with toxic algae that they act as poison for birds unlucky enough to eat them. It means a spurred growth of underwater vegetation as a result of clearer water and, from there, a reorganization of the food chain that many researchers believe will prove most injurious to native species. In short, it means bad times ahead for the Great Lakes (with the possible exception of Superior, which has consistently exhibited the smallest contingent of Quagga).

The even worse news is that traditional methods of handling Zebras don’t work on Quagga. What’s more, hardly anything works on Quagga. Scientists are stumped as to what can be done to eradicate these pests. This doesn’t mean there isn’t at least one tiny scrap of hope, however: Pseudomonas fluorescens, a bacteria prevalent in soil. Harmless to humans and most native fish, Pseudomonas fluorescens nevertheless acts as a molluscicide, a.k.a. deadly pill for both Quagga and Zebra mussels.

The even better news? Pseudomonas fluorescens doesn’t have to be active to be effective. Dead Pseudomonas bacteria remain strong enough to make dreissenids kick the proverbial bucket, establishing it as a crucial tool in the fight to protect our Great Lakes ecosystem if early studies pan out. It should be noted, however, that more research is needed to ensure the safety of such a measure on a large scale.

There’s no timetable on when we’ll know the effectiveness of treating Great Lakes mussels with soil bacteria. Another two decades might pass and alternative music could make a comeback before a stable solution is found. When–and if–it ever happens, for conservationists and lovers of the outdoors it can’t come soon enough.

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