Can Tree Rings Solve the Mystery of a 19th-Century American Shipwreck?

A wreck off the coast of Argentina is likely a Rhode Island whaling vessel from the 1850s

Measuring the ribs
Ignacio Mundo measures one of the ship’s ribs Courtesy of Mónica Grosso

In October 1858, an American whaling ship named the Dolphin set sail from Rhode Island and never returned home. Now, archaeologists believe they’ve identified the lost ship off the coast of far southern Argentina, according to a new study in the journal Dendrochronologia.

“It’s fascinating that people built this ship in a New England town so long ago, and it turned up on the other side of the world,” says Mukund Rao, a dendrochronologist at Columbia University and one of the paper’s authors, in a statement.

The remains of an unknown shipwreck first emerged from sediment near the coastal town of Puerto Madryn in 2004. Over the course of the next several years, archaeologists excavated the site and found artifacts that suggested the vessel might be the Dolphin. However, they couldn’t be sure and continued to sift through historical documents in search of clues about the ship’s true identity.

Shipwreck remains
The remains of a shipwreck at low tide near Puerto Madryn Courtesy of U. Sokolowicz

In 2019, the researchers had an idea: What if they looked at the tree rings of the vessel’s timber to determine the age and origins of the wood?

The scientists used a chain saw to cut several cross-sections from the vessel’s planking and ribs, which they then sent off for analysis. Dendrochronologists compared the wreck’s timber to a database of 30,000 trees dating back more than 2,000 years.

They determined that the vessel’s timber came from white oak and old-growth yellow pine trees. Comparing the wood to samples from specific regions, they determined that the pine likely came from Alabama, Georgia or northern Florida—regions that sent large amounts of pine timber to the northern states in the 19th century—and the white oak likely came from Massachusetts.

White oak cross section
A cross-section of one of the vessel’s ribs made from white oak  Courtesy of Ignacio Mundo

But what really convinced the researchers was the fact that the trees had been cut in 1849, which aligns with the Dolphin’s construction timeline.

“I was really excited,” Ignacio Mundo, a dendrochronologist at Argentina’s Laboratory of Dendrochronology and Environmental History and one of the study’s authors, tells the Boston Globe’s Brian Amaral. “The last ring corresponds to 1849, and knowing the Dolphin was launched in 1850, you say, okay, we are really close.”

Crews built the Dolphin between August and October 1850. The 111-foot-long whaler set sail on her maiden voyage on November 16.

For centuries, large vessels roamed the world’s oceans in search of whales. They hunted the massive marine mammals for their blubber, from which they extracted oil to use for lighting lamps and making soaps, as well as for their bones, which were handy for making corsets, children’s toys and other household items. Throughout the 20th century, whalers killed an estimated 2.9 million whales, which led to the “catastrophic decline” of worldwide populations, according to the nonprofit Natural Resources Defense Council. Despite a global moratorium that’s been in place since 1986, whaling continues in some countries today, including Japan, Iceland and Norway.

Throughout the 1850s, the 325-ton Dolphin roamed around the Atlantic and Indian oceans, venturing through the Azores and around the Horn of Africa. The ship set off on what would be its last voyage on October 2, 1858. Based on letters and other historical accounts, it likely crashed in Golfo Nuevo off the coast of Patagonia, some 10,000 miles from its home base of Warren, Rhode Island.

Diver at wreck
A diver inspects the shipwreck Courtesy of PROAS-INAPL

The scientists can’t rule out the possibility that the sunken ship is some other American whaler from around the same period. They are quick to point out that the dendrochronological findings do not constitute definitive proof—and they have not discovered more conclusive evidence, like the ship’s bell or the name on the hull.

However, it’s highly likely the vessel is the Dolphin and that the researchers finally solved the decades-old mystery.

“The archaeologists are more conservative—they prefer a slightly higher standard, and I don’t blame them,” says Rao in the statement. “It’s true we don’t have something like the ship’s bell. But for me, the story is there in the tree rings.”