Monday, November 30, 2020

"Svalbard’s Mysterious Disappearing Shipwrecks"

From Hakai Magazine:

When Øyvind Ødegård set out last June to scour the seafloor near Svalbard—a vast, ice-covered Norwegian archipelago halfway between continental Norway and the North Pole—he had a dream.

A marine archaeologist at the Norwegian University of Science and Technology, Ødegård has worked for decades to protect Norway’s underwater cultural heritage—the shipwrecks and other artifacts that lie, for most archaeologists, literally out of sight and out of mind. His dream was to discover, in these Arctic waters, wrecks that might rival those of the Franklin Expedition, found in Canada’s high Arctic in 2014 and 2016. Those ships, the HMS Erebus and HMS Terror, were so well preserved that after 170 years, divers found individual hairs entangled in combs.

Ødegård had reason to dream big: from the 1600s onward, thousands of European whaling vessels ventured to Svalbard to exploit its bowhead whale population, and at least 600 never left. Instead, they were entombed in crushing sea ice or sunk by rival fleets. Finding them could cast new light on an underexplored part of European history.

“Most European Arctic history from this period happened on ships, not land,” says Ødegård. “The only physical remains that can tell us a story about these lives will come from wrecks.”

Ødegård set off aboard the Arctic University of Norway’s (UiT) R/V Helmer Hanssen last summer, with the aim of finding Dutch ships sunk by the French in the 17th century. Using historical reports made to France’s King Louis XIV, Ødegård and his team pinpointed promising spots. But when they deployed underwater drones for a closer look, they not only failed to find Franklin-esque wrecks—they found nothing at all.

The absence suggested an awful possibility: the wrecks—which no one had attempted to find in the past—had been there, but had vanished. The suspected culprit? Shipworms, one of the world’s most voracious destroyers of underwater heritage.

Not a worm at all, shipworms are tunneling, tube-shaped mollusks that thrive on cellulose. A sizable infestation can destroy a sunken ship in just a few years, exposing to the elements the trove of historical treasures contained inside, from human remains to archaeological artifacts.

Shipworms have long been a recognized archaeological threat, but before 2016 no one realized they could endanger the abundant but unexplored wreckage sprawled across the Arctic seafloor, where it was assumed to be far too cold for them to thrive. That year, however, UiT marine biologist Jørgen Berge led an expedition (which also included Ødegård) to the water off Svalbard to investigate a Norwegian whaler called the Figaro, the world’s northernmost-known wreck. The Figaro appeared in good shape. But during the expedition, the team also hauled up a seven-meter tree trunk riddled with live shipworms.

The idea that shipworms may be threatening Arctic wrecks was reinforced in 2019 when Ødegård’s team found boreholes in wood collected from Svalbard beaches. A closer inspection of the Figaro also turned up previously missed evidence of shipworm infestation....