Jannah Theme License is not validated, Go to the theme options page to validate the license, You need a single license for each domain name.
News

The race is on to find Great Lakes wrecks before quagga mussels destroy them


MADISON, Wis. (AP) — The frigid fresh water of the Great Lakes kept shipwrecks so well preserved that divers could see the dishes in the cupboards. The downed planes that spent decades underwater were so intact they could practically fly again when archaeologists finally discovered them.

Now an invasive mussel is destroying shipwrecks deep in the lakes, forcing archaeologists and amateur historians to race against time to find as many sites as possible before the region hits eight U.S. states and the Canadian province of Ontario loses all physical trace. trace of its centuries-old maritime history.

“What you have to understand is that every shipwreck is covered in quagga mussels in the lower Great Lakes,” said Wisconsin state maritime archaeologist Tamara Thomsen. “Everything. If you drain the lakes, you’ll get a bowl of quagga mussels.

Quagga mussels, finger-sized molluscs with voracious appetites, have become the dominant invasive species in the lower Great Lakes over the past 30 years, biologists say.

The creatures covered virtually every wreck and downed plane in every lake except Lake Superior, archaeologists say. The mussels burrow into the wooden containers, building up in layers so thick that they eventually crush walls and decks. They also produce acid which can corrode steel and iron ships. No one has found a viable way to stop them.

Quagga mussels line the bell of the wreck of the Schooner Trinidad at the bottom of Lake Michigan in July 2023. Archaeologists are racing to locate Great Lakes shipwrecks before quagga mussels disintegrate them. (Tamara Thomsen via AP)

Michigan State maritime archaeologist Wayne Lusardi is pushing to recover more parts from a World War II plane flown by a Tuskegee Airman that crashed into Lake Huron in 1944.

“Divers started discovering (airplanes) in the 1960s and 1970s,” he said. “Some were so preserved that they could fly again. (Now) when they are removed, the planes look like Swiss cheese. (The quaggas) literally burn holes there.

Quagga mussels, native to Russia and Ukraine, were discovered in the Great Lakes in 1989, around the same time as their famous cousin species, the zebra mussel. Scientists believe the creatures arrived via ballast discharges from transoceanic cargo ships heading to Great Lakes ports.

Unlike zebra mussels, quaggas are hungrier, more resilient, and better tolerate colder temperatures. They devour plankton and other suspended nutrients, eliminating the base level of food chains. They consume so many nutrients at such high rates that they can make parts of the Great Lakes as clear as tropical seas. And while zebra mussels prefer hard surfaces, quaggas can attach to soft surfaces at greater depths, allowing them to colonize even sandy lake bottoms.

After 30 years of colonization, quaggas have replaced the zebra mussel as the dominant mussel in the Great Lakes. Zebras made up more than 98 percent of Lake Michigan’s mussels in 2000, according to the University of California Center for Invasive Species Research. Five years later, quaggas accounted for 97.7%.

For wooden and metal ships, quagga success meant overwhelming destruction.

The molds can burrow into sunken wooden boats and stack on top of themselves until details such as nameplates and carvings are completely obscured. Divers who attempt to brush them inevitably remove wood. Quaggas can also create clouds of carbon dioxide, as well as fecal matter that corrode iron and steel, accelerating the decomposition of metal wreckage.

The Quaggas have not yet established a foothold in Lake Superior. Biologists think the water contains less calcium, which quaggas need to make their shells, said Dr. Harvey Bootsma, a professor in the School of Freshwater Sciences at the University of Wisconsin-Milwaukee.

This means that the remains of the Edmund Fitzgerald, a cargo ship that sank in this lake during a storm in 1975 and was immortalized in Gordon Lightfoot’s song, “The Ballad of the Edmund Fitzgerald,” are in security, at least for the moment.

Lusardi, the Michigan State maritime archaeologist, has compiled 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 Strait of Mackinac in 1965, killing eight people. crew members. It also listed the Carl D. Bradley, another freighter that sank 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 crashed into 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 Airfield in Alabama during World War II.

Brendon Baillod, a Great Lakes historian based in Madison, has spent the past five years researching the Trinidad, a grain schooner that sank in Lake Michigan in 1881. He and fellow historian Bob Jaeck eventually found the wreck in July off the coast of Algoma, Wisconsin. .

The first photos of the site, taken by a robot vehicle, showed the ship was in unusually good condition, with the rigging intact and the dishes still in the cabins. But the site was “completely covered” with quagga mussels, Baillod said.

“It’s been completely colonized,” he said. “Twenty years ago, even fifteen years ago, this site would have been clean. Now you can’t even recognize the bell. You cannot see the name table. If you brush these molds, they pull the wood off with them.

Options for managing quaggas could include treating them with toxic chemicals; covering them with tarpaulins that restrict water flow and deprive them of oxygen and food; introduce predatory species; or suffocate them by adding carbon dioxide to the water.

So far, nothing looks promising on a large scale, said UW-Milwaukee’s Bootsma.

“The only way they could disappear from a lake as large as Lake Michigan is because of disease, or possibly an introduced predator,” he said.

This leaves archaeologists and historians like Baillod scrambling to locate as many wrecks as possible to map and document before they disintegrate under quagga onslaught.

At stake are the physical remains 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 these tangible, preserved time capsules of our history, we lose our tangible connection to the past,” Baillod said. “Once they’re gone, it’s all just a memory. It’s just stuff in the books.


whnt

Back to top button