Today they are more common on the Asian menu, but seaweed and other aquatic plants may once have been an important source of food in Europe too. This emerges from traces that researchers discovered in the fossil tartar of people from different parts of Europe. Evidence of the consumption of macroalgae or freshwater plants extends from 8,000 years ago to the early Middle Ages. Apparently these aquatic food resources only became uncommon relatively late. Now it could be worthwhile to continue the old tradition, say the scientists.
As is well known, they play an important role in some parts of Asia today: numerous types of algae and other aquatic greens are used there as food and in medicine. In our country, however, the aquatic plants are considered exotic – they are only represented in exceptional cases in traditional Western cuisine. But has it always been like this? There are only a few archaeological and historical indications of its use. Traces of algae at archaeological sites have previously been interpreted as the remains of fuel, fertilizer or animal feed. The extent to which the few historical mentions of collecting algae from the early Middle Ages reflect a common practice at the time also remained questionable. At least in later times, eating aquatic plants was seen as an emergency solution in times of famine, which may have made it unusual.
Traces in the tartar
The current evidence of a once more widespread consumption of aquatic foods now comes from a special source: As part of their study, scientists led by Stephen Buckley from the University of York examined fossil tartar from the remains of former inhabitants of Europe for traces of food. These were finds from 28 archaeological sites across Europe – from northern Scotland to the Baltics to Portugal. They cover the period from 8,000 years ago to the early Middle Ages. The tartar samples obtained were subjected to a modern analysis method that can reveal tiny components of the food that were once trapped and preserved in the plaque when consumed.
As the team reports, they actually found biomarkers in some of the 74 samples that indicated the person’s consumption of different foods. The scientists then discovered the signatures of the special plants in a surprising number of them: “In 26 samples, we identified seaweed (macroalgae), freshwater algae or aquatic plants based on their distinctive, unusual and complex organic chemistry,” the scientists write. It fits into the picture that they found traces of seaweed consumption in areas closer to the coast and those of consumption of freshwater plants in more inland locations.
A lost food resource?
Specifically, the team found evidence of the consumption of red, brown or green sea algae in samples from Scotland and Spain that are up to 8,000 years old. The researchers identified traces of aquatic freshwater plants, such as pondweed and freshwater algae, in samples from Portugal, Scotland and Lithuania. The period of evidence covered the Middle and Neolithic periods as well as the Bronze Age and the early Middle Ages.
Buckley particularly emphasizes: “This new evidence not only shows that seaweed was consumed in Europe during the Mesolithic period around 8,000 years ago, when intensive use of marine resources was known, but also that this continued into the Neolithic period. “It’s actually thought that the introduction of agriculture during this period led to the abandonment of marine resources,” says Buckley. “The results now strongly suggest that these ancient peoples knew the nutritional benefits of seaweed so well that they maintained their connection to the sea,” says the scientist.
Co-author Karen Hardy from the University of Glasgow also sees the findings as a message for our society today: “The study highlights the potential for the rediscovery of alternative, local and sustainable food resources. “It was very exciting to be able to show that algae and freshwater plants were eaten over a long period of time in our European past,” said the researcher.
Source: University of York, specialist article: Nature Communications, doi: 10.1038/s41467-023-41671-2