Bogs are perhaps best known for preserving prehistoric human remains. One of the most famous examples of these so-called “bog bodies” is Tollund Man. (Getty Images)
Peat bogs are notoriously uninhabitable. When low in oxygen, they don’t support microbial life, and without microbes, dead humans and animals caught in the spongy wetlands fail to decompose. Thanks to this unusual characteristic, peat bogs have long been the scene of incredible archaeological discoveries, including naturally mummified human remains known as bog bodies.
But new research published in the journal PLOS One presents evidence that bogs are losing their body-preserving abilities. As Cathleen O’Grady reports for Science magazine, archaeologists found that the best-preserved artifacts recovered from bogs in 2019 resemble the worst-preserved ones found in the 1970s, while the best-preserved specimens from the ’70s are on par with the worst retrieved in the 1940s. (Bogs’ lack of oxygen, as well as an abundance of weakly acidic tannins, preserves artifacts as delicate as small mammal and bird bones.)
The findings suggest that archaeologists may need to act quickly to uncover what’s left in the world’s bogs.
“If we do nothing, wait and hope for the best, it is likely that the archaeo-organic remains in many areas will be gone in a decade or two,” the authors say in a statement. “Once it is gone there is no going back, and what is lost will be lost forever.”
Per the paper, the team suspects that human activities like excavation and farming have introduced oxygen into the bog’s watery mix. When the element reacts with chemicals in the bog, it creates sulfuric acid, which is highly corrosive. Drought and flooding caused by climate change may have exacerbated the situation further.
As the archaeologists conclude in the statement, “If the organic remains deteriorate, these type of analyses will not be possible to do anymore, and given the information we are now generating from them, it will be a devastating blow to our understanding of ancient cultures, diet and subsistence strategies, migration and mobility.”
https://www.smithsonianmag.com/smart-news/peat-bogs-arent-preserving-ancient-bones-well-they-used-180975449/