Climate change threatens Lake Champlain’s historic shipwrecks - WCAX

Climate change threatens Lake Champlain’s historic shipwrecks

FERRISBURGH, Vt. (WCAX) - Climate change has prompted questions about the long-term health of shipwrecks on Lake Champlain, including two new wrecks that were supposed to have opened to divers this summer. In part 2 of her special report, Cat Viglienzoni looks at how the changing climate is having an impact on efforts to preserve the region’s history at the bottom of the lake.

Lake Champlain holds a lot of history deep underneath the water’s surface. Boats motor over the many of the state’s historic preservation sites. Some 300 or more shipwrecks rest on the lake floor and documenting them might be a race against time.

“We’re certainly very concerned about the long-term implications of global warming and climate change on the shipwrecks and their long-term preservation,” said Chris Sabick with the Lake Champlain Maritime Museum. He says they’ve gotten anecdotal evidence of changes at some of the historic shipwrecks.

Now, the museum is trying to figure out the best way to get data-based research to document the long-term effects of climate change on the shipwrecks. Sabick says warmer water can speed up the breakdown of wooden ship components currently preserved in cold, fresh water. “The more activity there is, the faster they’re going to break down,” he said.

And warmer waters open the door to the spread of a dreaded invasive species, the zebra mussel, which coats and damages wrecks. “Once they’re there, they’re there. That’s why documenting these and understanding what’s there is so important because there’s a window of opportunity that we might not always have,” said Laura Trieschmann, Vermont’s state historic preservation officer.

She says $60,000 in new money to document the lake’s canal boat history will help them make sure the wrecks aren’t lost to time. “We want to look at these wrecks so we understand how we’ve used Lake Champlain, how we can better use Lake Champlain, how our history has evolved... It helps us understand our history.”

But the rains this summer moored many archaeological efforts to create 3D models of the shipwrecks. “We have continued to do some diving in the lake but there’s not much to see right now with all that runoff from the excessive rainfall that we had this year,” Sabick said. He hopes the silt will settle down enough in the coming weeks to allow them to continue photographing some of the sites next month. And he says the poor visibility also meant two dive sites at the mouth of the Otter Creek were closed this season because they weren’t safe. “It’s not an environment that we want to encourage divers to visit, even though these are some of my favorite shipwrecks in the lake.”

Not all of the Maritime Museum’s archaeology work was washed out though. At Arnold’s Bay in Panton, his team has spent the summer exploring the remains of Benedict Arnold’s flagship, the Rogue Alley Congress, which met its demise during the Revolutionary War after the Battle of Valcour Island. “it happened basically right here in our backyard,” Sabick said.

The museum got a grant from the American Battlefield Protection Program to try to establish the boundaries of where the American soldiers sank and burned their five ships -- including the Congress -- to avoid British capture.”Honestly, the artifact density has been so...has been so dense that we haven’t been able to identify clusters. That would suggest that those were where the sinking locations were. So, that’s been a blessing and a curse I guess... We have too much data!” Sabick said.

So did the wet weather this summer leave recreational divers high and dry? Yes and no. Divers with the museum had a couple fewer spots to visit and the Waterfront Diving Center in Burlington says increased sediment definitely made visibility worse than in past years. But they also say that’s not stopping experienced divers, and that their season has been busy.

Related Story:

Divers will soon be able to visit 2 new Lake Champlain shipwrecks

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