A new study uses the bones of the preserved fish to confirm the Vikings' ancient trade routes.
According to Ars Technica, the Norwegian researchers were already aware that the Vikings traversed a trade route across the ocean at least 800 years ago, but environmental biologists at the University of Oslo were able to use the DNA in the cod bones—discarded by the Vikings along their journey—to confirm that these trade trips took place 200, even 400, years earlier than they first suspected.
In a study published in the Proceedings of the National Academy of Sciences, the team explains that they used DNA analysis to identify the origins of 15 different cod to Germany, Norway, and the United Kingdom. They then compared the DNA in the ancient cod to that of their modern counterparts, to determine that the fish have remained in the same breeding grounds and migration routes for more than a thousand years.
“By extracting and sequencing DNA from the leftover fish bones of ancient cargoes at Haithabu [an ancient Viking trading settlement near Germany], we have been able to trace the source of their food right the way back to the cod populations that inhabit the Barents Sea, but come to spawn off Norway's Lofoten coast every winter,” James Barrett, an archaeologist at the University of Cambridge, and one of the study’s co-authors, said in a statement.
Freeze dried cod, which can preserved for many years, is a popular dish in Norway even to this day. The Vikings were partial to the meal, as it could sustain them over the course of their long trade journeys. The cod bones the scientists studied were eaten in Haithabu, the Viking trade outpost, around 1,200 years ago, perhaps proving—along with the fact that the storied journeys of the Vikings actually took place—that human taste in food hasn’t really changed too much, either.