An underwater stone wall discovered in the Baltic Sea near Germany was built about 11,000 years ago to hunt reindeer when the site was land, a new study indicates.
Researchers suggest that local prehistoric people built the wall; Its remaining parts were crafted from 1,670 stones and extend approximately two-thirds of a mile (975 meters) long, measuring 3 feet (1 m) high and 6.5 feet (2 m) wide. The team discovered the wall using sonar and dove to the site, which is located at a depth of about 21 m (70 ft) and about 10 kilometers (6 mi) east of Rerik, Germany, in Mecklenburg Bay. .
The wall may be the largest of its kind since the early Holocene (11,700 years ago to the present) in Europe, the researchers said in the study. Based on similar prehistoric walls, including the ancient “desert kites” found in the Middle East: The authors propose that it was built on dry land by hunter-gatherers to drive herds of wild animals to pens where they could be killed. They also suggest that the wall in Mecklenburg Bay was used to hunt reindeer. (fenced rangefer), which was a common species in that part of Europe at the time.
But changes in sea level caused by melting ice sheets after the last ice age flooded the area about 8,500 years ago, along with other parts of the modern Baltic and the “Doggerland” region that linked Great Britain and the European continent.
Scientists spotted the wall almost by accident in 2021, during a boat trip to Mecklenburg Bay to teach marine geophysics techniques to students.
“It was a little unexpected.” Jacob Geersen, a marine geophysicist at the University of Kiel in Germany told Live Science. “We didn’t look for the structure because we didn’t know it was there, but we resolved it on the seafloor from data from our multibeam echo sounder.”
Researchers have now mapped the wall using sonar equipment on ships and in a autonomous underwater vehicle, and researchers have conducted dives at different sites along its length. Those investigations and sediment samples from the seafloor around the structure indicate that it was intentionally built on dry land, rather than being a natural feature of the now submerged landscape.
Bradtmöller explained that the wall appears to have been built along the edge of an ancient swamp or lake that would have prevented the herd’s animals from escaping in that direction.
The date the wall was built is not known precisely, he said, but reindeer are believed to have become extinct in the area about 9,000 years ago, a few hundred years before the sea flooded it.
In addition to mapping the wall, researchers hope to find buried artifacts along its length that could reveal more about the wall’s origins and use. They suggested that parts of the wall could have been “shutters” where the people tasked with killing the animals could have hidden so as not to scare away a panicked herd.
Partly due to the water’s low-oxygen environment, submerged structures are often well preserved. But studying them can be challenging, the authors noted. The Mecklenburg Bay wall, however, is located in relatively sheltered waters along the Baltic coast, unlike structures in the Doggerland region of the North Sea, where storms and high waves are common, Geersen said.
In addition to better preserving the structure, the softer waters make it easier to investigate the wall, he said; Researchers hope to return to the site in a few months.
Vincent Gaffneyan archaeologist at the University of Bradford in the United Kingdom who was not involved in the study but is a Doggerland key researchertold LiveScience that the wall, if confirmed to be a man-made structure, “clearly demonstrates that our coastal shelves, many of which were habitable before sea level rise after the last ice age, have likely preserved evidence of prehistoric lifestyles are rarely preserved on earth.”
Many now-submerged sites are being developed for coastal or marine structures, so the discovery shows “the need to explore these areas, which are currently unknown land (Latin for unknown land),” he said in an email.