The Great Lakes’ frigid fresh water used to keep shipwrecks so well preserved that divers could see dishes in the cupboards. Downed planes that spent decades underwater were left so pristine they could practically fly again when archaeologists finally discovered them.
Now, an invasive mussel is destroying shipwrecks deep in the depths of the lakes, forcing archeologists and amateur historians into a race against time to find as many sites as they can before the region touching eight U.S. states and the Canadian province of Ontario loses any physical trace of its centuries-long maritime history.
“”What you must understand is that every shipwreck in the Lower Great Lakes is covered by quagga mussels,” Wisconsin maritime archaeologist Tamara Thomsen explained. “Everything. If you drain the lakes, you’ll get a bowl of quagga mussels.”
Quagga mussels, finger-sized mollusks with voracious appetites, have become the dominant invasive species in the lower Great Lakes over the past 30 years, according to biologists. Archaeologists claim that the creatures cover nearly every plane and shipwreck in the Great Lakes, except Lake Superior. The mussels burrow into wooden vessels, building upon themselves in layers so thick they will eventually crush walls and decks. The mussels also release acid which can cause steel and iron vessels to corrode. No one has found a viable way to stop them.
Wayne Lusardi, Michigan’s state maritime archaeologist, is pushing to raise more pieces of a World War II plane flown by a Tuskegee airman that crashed in Lake Huron in 1944.
“Divers started discovering (planes) in the 1960s and 1970s,” he said. Some were preserved so well that they could have flown again. When they are removed, the planes look more like Swiss cheese. (Quaggas are) literally burning holes in them.”
Quagga mussels, native to Russia and Ukraine, were discovered in the Great Lakes in 1989, around the same time as their infamous cousin species, zebra mussels. Scientists think the animals arrived from ballast dumps of transoceanic cargo ships making their way into Great Lakes port.
Unlike zebra mussels, quaggas are hungrier, hardier and more tolerant of colder temperatures. The quaggas eat plankton, and any other nutrients suspended in the water. This eliminates food chains at their base. They consume so many nutrients at such high rates they can render portions of the murky Great Lakes as clear as tropical seas. While zebra mussels prefer harder surfaces, quaggas are able to attach themselves to soft surfaces and at a greater depth, which allows them to colonize the sandy bottoms of lakes.
After 30 years of colonization, quaggas have displaced zebra mussels as the dominant mussel in the Great Lakes. Zebras made up more than 98% of mussels in Lake Michigan in 2000, according to the University of California, Riverside’s Center for Invasive Species Research. Five years later, quaggas represented 97.7%.
For wooden and metal ships, the quaggas’ success has translated into overwhelming destruction.
The quaggas can burrow in sunken wooden vessels, stacking on themselves to obscure details like nameplates and carvings. Divers will inevitably remove some wood when they try to scrub them away. Also, Quaggas can produce clouds of carbon dioxide, and feces which corrode steel and iron, speeding up the decay of metal ships.
Quaggas have yet to establish a foothold in Lake Superior. Biologists believe the water there contains less calcium, which quaggas need to make their shells, said Dr. Harvey Bootsma, a professor at the University of Wisconsin-Milwaukee’s School of Freshwater Sciences.
That means the remains of the Edmund Fitzgerald, a freighter that went down in that lake during a storm in 1975 and was immortalized in the Gordon Lightfoot song, “The Ballad of the Edmund Fitzgerald,” are safe, at least for now.
Lusardi, Michigan’s state maritime archaeologist, ticked off a long list of shipwreck sites in the lower Great Lakes consumed by quaggas.
His list included the Daniel J. Morrel, a freighter that sank during a storm on Lake Huron in 1966, killing all but one of the 29 crew members, and the Cedarville, a freighter that sank in the Straits of Mackinac in 1965, killing eight crew members. He also listed the Carl D. Bradley, another freighter that went down during a storm in northern Lake Michigan in 1958, killing 33 sailors.
The plane Lusardi is trying to recover is a Bell P-39 that went down in Lake Huron during a training exercise in 1944, killing Frank H. Moody, a Tuskegee airman. The Tuskegee Airmen were a group of Black military pilots who received training at Tuskegee Army Air Field in Alabama during World War II.
Brendon Baillod, a Great Lakes historian based in Madison, has spent the last five years searching for the Trinidad, a grain schooner that went down in Lake Michigan in 1881. In July, he and Bob Jaeck found the wreck off Algoma in Wisconsin.
The first photos of the site, taken by a robot vehicle, showed the ship was in unusually good shape, with intact rigging and dishes still in cabins. Baillod stated that the area was “fully carpeted with” quagga mules.
“It is completely colonized, he added. “Twenty years ago, even 15 years ago, that site would have been clean. Now you can’t even recognize the bell. The nameboard is hidden. If you brush those mussels off, it tears the wood off with it.”
Quagga management options could include treating them with toxic chemicals; covering them with tarps that restrict water flow and starve them of oxygen and food; introducing predator species; or suffocating them by adding carbon dioxide to the water.
So far, Bootsma of UW-Milwaukee said that nothing seems promising at a larger scale.
“The only way they will disappear from a lake as large as Lake Michigan is through some disease, or possibly an introduced predator,” he said.
That leaves archaeologists and historians like Baillod scrambling to locate as many wrecks as possible to map and document before they disintegrate under the quaggas’ assaults.
At stake are the physical remnants of a maritime industry that helped settle the Great Lakes region and establish port cities such as Milwaukee, Detroit, Chicago and Toledo, Ohio.
“When we lose those tangible, preserved time capsules of our history, we lose our tangible connection to the past,” Baillod said. Once they are gone, all that remains is a mere memory. It’s all just stuff in books.”
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