Climate Change Won’t Even Leave Shipwrecks Alone

Drought in parts of Europe has been so bad this summer that big rivers like the Danube and the Vistula have shrank down to shadows of their usual selves. The result: Nazi shipwrecks.

As CNN reported this week, persistent drought and falling water levels revealed the remains of several ships in or around towns like Prahovo, in Serbia. The ships are among hundreds sunk intentionally by the Nazis in 1944, on the run from Soviet forces. This can cause some issues for river navigation, not to mention for historical preservation or study — because people steal stuff or break off pieces of the exposed ships, and because exposure to air and sunlight can accelerate their decomposition.

This latest indignity for the world’s sunken vessels feels like an odd indicator of climate change’s global perversions, an almost perpendicular signal to the more standard warnings of too hot, too wet, too on fire. And the Danube’s hidden wrecks are far from the first to feel the effects.

Droughts have uncovered ships along the Mississippi River, in Lake Mead, and at various places around the long Australian coastline. Storms have sent old wrecks washing ashore in Newfoundland, where hurricanes’ effects aren’t often felt. The most dramatic example may be the Aral Sea, where decades of ill-advised engineering projects and water use now combine with climate change to bring the lake to its knees.

While its dropping water levels in drought-stricken rivers and lakes that do it, rising sea levels also play a role, helping erode shorelines and revealing wrecks in places like Florida and North Carolina. “As the ocean rises,” one expert told the New York Times earlier this year, “it’s digging things out that have been buried or hidden for more than a century.”

While exposure to air and handsy people obviously will have an impact, just the changing chemistry of the planet is also likely harming old wrecks that remain submerged. As the North Carolina Office of State Archeology has pointed out in discussion of the USS Huron site, the ocean has warmed an average of at least two degrees Fahrenheit since that ship went down in the 1870s.

“This warming affects the preservation conditions of the wreck, leading to increased corrosion in the iron hull structure. The warmer waters have also caused tropical organisms like fish, mussels, invertebrates, and microorganisms to move farther north, altering the biological interactions at the site. This can result in the breakdown of remaining wooden features by common shipworms, damage caused by larger fish, and the introduction of invasive species with uncertain consequences.”

In Europe, rainfall is expected soon that will raise the Danube’s levels back up to normal, resubmerging the exposed boats. But they, or others like them, will poke their keels and hulls and cracked masts back above water soon enough.