Scientists learn how Sahara desert change over thousand years

A picturesque green land, rich in reservoirs, was still “some” 5-10 thousand years ago, the modern Sahara. In other words, there was no desert here before. The ancient people living in this area, unlike modern North Africans, did not suffer at all from drought. Moreover, their primary food was fish. Scientists came to such sensational conclusions after discovering many unexpected artifacts in the Sahara.

Archaeological data sheds light on how ancient people lived in this area of North Africa. According to a report released in the open-access journal PLOS ONE in the Sahara Desert, in the southwestern Libyan Acacus Mountains, near the border with Algeria, almost 18 thousand remains of certain species were found, about 80% were fish – for example, catfish and tilapia.

The fossils found indicate that from 10,200 to 4,650 years ago, during the early middle and present geological period of the Holocene, a significant part of the wildlife here was made up of fish despite the abundance of mammals. Also, in the desert, insects, rodents, freshwater mollusks, and amphibians were found in smaller numbers.

Archaeologists working in the Tadrart Akakus mountains, in the area of the Takarkori rock shelter, unearthed the bones of fish, toads, frogs, crocodiles, and birds and concluded that all these remains are mainly human food waste. Many bones show cut marks and burn marks. “After examining the remains, we concluded that, despite the presence of mammals, fish was the main food for people who lived about 10 thousand years ago in this region,” scientists say.

In other words, the ancient people actively caught fish and ate it, having previously fried it over a fire.

By the way, in this region, there was an abundance of Clarias – a fish from the catfish genus. It is large and lacks scales. In addition, Clarias can breathe atmospheric air and move on wet ground.

The critical find is undoubtedly the remains of a fish. While this is not uncommon in early Holocene contexts throughout North Africa, the amount of fish we have found and studied in central Sahara is unprecedented, ”notes Savino Di Lernia, a fellow at the Sapienza University of Rome and the University of the Witwatersrand of South Africa.

The study adds new information about climate change and cultural adaptations in the region. Particularly intriguing is that fish was common in the diets of early pastoralists.

“The number of fish remains is staggering. I especially liked the fact that the early shepherds were pretty good fishermen, and fish was an important staple of their diet,” said Di Lernia.

Today it is windy, hot, and scorched in these parts. But the fossils found show that for much of the early and middle Holocene, this region — like other parts of Central Sahara — was humid and rich in water, as well as plants and animals. By the way, prehistoric people who lived here in large numbers left behind several famous rock paintings.

A deposit of bluish-gray, olive and black, loamy and clayey sand, including a rich fauna of freshwater mollusks, is exposed in the basin’s most “depressed” part. This sediment forms in the aquatic environment (from lake to swamp). And the grayish-black sand, rich in organic matter, is located on the outskirts of bogs corresponding to the coastline of former ponds, the scientific article notes.

Alas, over the next millennia, this area became drier and thus less able to support stagnant bodies of water that are home to fish. This climate change is reflected in the results of the study.

For example, in the Wadi Tanezzuft Valley (Tassili Plateau), a large aquifer supported the Tanezzuft River, which flowed approximately 200 km from south to north, ending north of the Tadrart Akakus Massif.

Surface groundwater supported several ponds. The side branch of the Tanezzuft River has fed Lake Garat-Ouda for several millennia. The Tanezzuft River has existed for several millennia, gradually shortening its length and supporting a vast oasis. In the middle of the late Holocene, a decrease in the river flow provoked the interruption of its connection with the Garat-Ouda lake, which dried up over several decades, the article specifies. Ghat and Al Barkat’s oases have several reservoirs with underground feeding, which were active several decades ago.

This is confirmed by archaeological finds: about 90% of all animal remains that lived here, according to the analysis of bones, from 10,200 to 8,000 years ago, were fish, but in the period from 5900 to 4650 years ago, this number has already decreased by 40%.

This environmental change has forced hunter-gatherers, who once relied practically on fish, to adapt and change their diet. Scientists have noted a shift over time towards eating more mammals.

According to the authors of the study, the findings provide crucial information about the dramatic climate changes that have led to the formation of the largest and hottest desert in the world.

The Takarkori rock shelter has once again proved that it is a real treasure for African and world archeology. This territory can be called a natural place for reconstructing the complex dynamics of the interaction of ancient groups of people with their environment in a changing climate, the scientists said in a statement.