Quagga mussel invasion threatens preservation of shipwrecks in the Great Lakes

In a war against time, archaeologists and historians are vigorously searching to uncover the remnants of shipwrecks and downed aircraft in the Great Lakes region. This undertaking aims to secure and document the crucial pieces of the area’s extensive maritime history before the invasive quagga mussels obliterate all tangible evidence.

The Great Lakes, which border eight U.S. states and the Canadian province of Ontario, have been the victim of these voracious mussels, primarily in the lower Great Lakes, over the last three decades. Tamara Thomsen, a Wisconsin state maritime archaeologist, warns, “Every shipwreck is covered with quagga mussels in the lower Great Lakes… If you drain the lakes, you’ll get a bowl of quagga mussels.”

What are quagga mussels?

Quagga mussels, originating from Ukraine’s Dnieper River drainage, compromise the integrity of wooden ships by boring through them and stacking up in thick layers, causing structural failures. They also release acids capable of corroding steel and iron vessels.

The destructive power of these small invaders leaves submerged aircraft resembling “Swiss cheese,” corroding and burning holes into the remnants, as depicted by Wayne Lusardi, Michigan’s state maritime archaeologist.

Lusardi has been actively involved in uncovering more from the 1944 crash site of a World War II aircraft in Lake Huron, piloted by a Tuskegee airman. The prolific presence of quaggas has made this task increasingly crucial, as each uncovered artifact carries with it the visible scars and damages inflicted by these mollusks.

Devastating quagga invasion

However, Lake Superior remains a bastion against the quagga invasion due to its lower calcium levels, inhibiting the mussels’ ability to form their shells. This has offered temporary sanctuary to the remnants of ships like the Edmund Fitzgerald, which sank in 1975.

Shipwrecks such as the Cedarville, Carl D. Bradley, and Daniel J. Morrell are just a few examples listed by Lusardi where the relentless mussels have left their mark, obliterating significant portions of the historical wrecks. These ships, which witnessed tragic losses, now face a silent adversary, compromising our ability to study and understand our maritime past.

The focus is not only on vessels but also on submerged aircraft. Divers, since the 1960s, have discovered aircraft so well preserved they could potentially take to the skies again. But the pervasive quagga mussels are fast compromising this underwater time capsule, corroding and consuming these relics.

Great Lakes historians, like Brendon Baillod, are also in a race against time to locate and document ships like the Trinidad, a grain schooner which sank in 1881. This ship, found off Algoma, Wisconsin in July, presented a stark visual of the quagga infestation, the site being “fully carpeted” with them, compromising the integrity of the ship’s structure and its identifiable features.

Zebra mussels are also causing problems

The invasion of quagga mussels, discovered in 1989 alongside the notorious zebra mussels, entered the Great Lakes through ballast dumps from transoceanic freighters. They are more resilient, tolerant to lower temperatures, and have larger appetites compared to their zebra counterparts, causing more extensive destruction by consuming plankton and suspended nutrients, which are foundational to food chains in the lakes.

The severe clarity they bring to some parts of the once murky Great Lakes might appear beneficial at first glance, but it is a clear indication of the ecological imbalance and historical destruction caused by these invaders.

The destruction of these maritime artifacts represents a loss of tangible connections to our past, severing the links to the history of port cities like Milwaukee, Detroit, Chicago, and Toledo, Ohio. The Great Lakes, which were essential in the settlement and establishment of these cities, are losing their physical narratives to the invasive mussels.

Once these tangible links are gone, we are left with mere memories and written records, making the quest to uncover and preserve them all the more urgent and essential. The rapid pace of this silent destruction underscores the importance of acting now to preserve our submerged heritage before it disappears into the shadows of the past.