Archaeologists, historians and divers are trying to digitally capture more than 1,000 shipwrecks at the bottom of the Great Lakes before they become unrecognizable after a combination of invasive mussels and climate change has accelerated their deterioration at an alarming rate.
The Great Lakes region is known among diving circles as one of the best places in the world to explore shipwrecks because the cold, fresh water offers ideal conditions for their preservation, even in shallow water.
Now, the deterioration of these underwater relics has not only been accelerated by more frequent and intense storms believed to be caused by climate change, but also by the colonization of the lakes by invasive zebra and quagga mussels from Europe, probably introduced into the Great Lakes through ballast water from international cargo ships.
Since their arrival in the 1980s, these thumbnail-sized mollusks have transformed the Great Lakes, pushing local mussels to the brink of extinction, turning once-murky turquoise waters crystal clear while covering almost everything. , from docks to power plants. in an irregular carpet of densely packed shells.
Shipwrecks are reduced to “piles of wood”
Durrell Martin has witnessed that change firsthand. Throughout his 30-year diving career, Martin, also president of the nonprofit group Save Ontario Shipwrecks, said invasive mussels have totally transformed the underwater world.
When it began, lights were needed to penetrate the murky darkness of the lakes. Back then, divers had to get closer to see the wreck, but when they did they could still see plates, preserves, and even the original wood from 200-year-old ships lying on the bottom.
Today, the water is so clear that lights are often no longer needed, and although divers can now easily see the shape of the shipwrecks, they are embedded in living layers of tens of thousands of invasive shellfish.
“Our dilemma is that, yes, visibility is great for divers, and we can now enjoy and see more of the wrecks, but they are disintegrating at a faster rate than ever before.”
The shipwrecks that we thought would be here in another 200 years and that we could enjoy, we realized that probably within the next 10 to 20 years, they will all be gone. There will be piles of wood at the bottom.– Durrell Martin, President, Save Ontario Shipwrecks
Mussels attach themselves to surfaces using a bundle of threads called filaments. On wooden shipwrecks, they use these tendrils to burrow into the wood, giving them a firm grip, but weakening the integrity of the wood. On steel and iron, mussels produce an acid in their feces that corrodes the metal.
The hull of a boat is designed to displace water. It is meant to resist pressure from below, not from above. Over the years, the filaments and acid weaken the boat’s materials and the entire boat eventually collapses under the weight of the mussels attached to them.
“We can’t stop this,” Martin said. “We thought the shipwrecks would be here in another 200 years and we could enjoy them; we realized that probably in the next 10 to 20 years they will all be gone. They will be piles of wood at the bottom.”
Lack of data on an estimated 6,000 shipwrecks
He The problem has been documented. in a series of studies going back decadesBut governments on both sides of the border have done almost nothing, according to Ken Meryman, a shipwreck hunter and diver from Duluth, Minnesota, who has been documenting Great Lakes naval relics for 50 years.
“They’re collapsing,” he said of the 1,400 known shipwrecks in the Great Lakes.
Meryman added that shipwrecks are at risk from more than just invasive bivalves: Studies suggest that bacteria are also being overloaded by climate change..
“In the remains of steel there is a bacteria that feeds on iron,” Meryman said. “We have that in Lake Superior and in the steel debris. It’s caused deterioration. I’m not sure what to do about it.”
The problem, according to Meryman, is the lack of data over the estimated 6,000 shipwrecks which are believed to be at the bottom of the Great Lakes. He said Canadian and American antiquities authorities have yet to document exactly what’s out there, its historical significance and the exact rate of decay.
“If you are going to manage shipwrecks, you would want to know: ‘Where are the most historically significant items represented and what risk is there of their deterioration?'”
The quest to map them all
That’s why Meryman, a retired computer programmer, has dedicated much of his golden years to documenting shipwrecks before they disappear using a 3D scanning technology called photogametry, which uses a series of images to form a 3D digital model.
Divers, historians and archaeologists from across the continent have worked with Meryman over the years to help him place those models in his 3Dwrecks website, where you can explore a catalog of 160 shipwrecks online to explore wrecks, such as Katie Eccleswhich sank in Lake Ontario in 1922, in complete detail.
“You can compare them, get a map of differences and know if the side of the ship is bulging and starting to collapse, if the deck has collapsed; you can tell if someone took an artifact,” Meryman said.
“There’s evidence, there’s documentation about what’s there. It’s not the primary purpose of the database, but it could be used for that.”
He said the data can also be used to show authorities that a shipwreck is worth saving, especially if it’s on a major shipping route, like the wreck of the Wilson Thomas near Duluth.
“Ships have been anchored in it for years… and they beat the crap out of it, but we can’t go to the Corps of Engineers and say, ‘Hey, we want a wreck buoy here,’ unless we have strong evidence that “Things have changed.”
Merymen said it plans to increase the number of 3D scans of Great Lakes shipwrecks available on its website to 200 “soon” and hopes to be able to map the estimated 1,400 shipwrecks that lie at a survivable depth over the next 20 years. years.
The more we know about our underwater history, he maintains, the more power the public has to know what should be saved, or if it can be saved.
“The database will be valuable to a lot of people,” he said, adding that he hopes the data might even help researchers one day find a way to keep invasive mussels away from shipwrecks.
“They are colonizing the shipwreck because it is a substrate that they can live in, but around it, it is not a substrate that they live in,” he said. “I’ve wondered about that a little bit. It could be very effective to use some kind of reduction process.”