World’s oldest runestone found in Norway, archaeologists say

Archaeologists in Norway have found what they claim is the world’s oldest runestone, saying the inscriptions are up to 2,000 years old and date back to the earliest days of the enigmatic history of runic writing.

The flat, square block of brownish sandstone has carved scribbles, which may be the earliest example of words recorded in writing in Scandinavia, the Museum of Cultural History in Oslo said.

It said it was “among the oldest runic inscriptions ever found” and “the oldest datable runestone in the world”.

“This find will give us a lot of knowledge about the use of runes in the early iron age. This may be one of the first attempts to use runes in Norway and Scandinavia on stone,” said Kristel Zilmer, a professor at the University of Oslo, of which the museum is part.

Older runes have been found on other items, but not on stone. The earliest runic find is on a bone comb found in Denmark. Zilmer said that maybe the tip of a knife or a needle was used to carve the runes.

The runestone was discovered in late 2021 during an excavation of a grave near Tyrifjord, west of Oslo, in a region known for several monumental archaeological finds. Items in the cremation pit – burned bones and charcoal – indicate that the runes were likely inscribed between AD1 and AD250.

“We needed time to analyse and date the runestone,” she said to explain why the finding was first announced on Tuesday.

Measuring 31cm by 32cm (12.2in by 12.6in), the stone has several types of inscriptions and not all make linguistic sense. Eight runes on the front of the stone read “idiberug” – which could be the name of a woman, a man or a family.

Zilmer called the discovery “the most sensational thing that I, as an academic, have had”.

There is still a lot of research to be done on the rock, dubbed the Svingerud stone after the site where it was found.

“Without doubt, we will obtain valuable knowledge about the early history of runic writing,” Zilmer said.

The runestone will be exhibited for a month, starting on 21 January, at the Museum of Cultural History, which has Norway’s largest collection of historical artifacts, from the stone age to modern times.

Runes are the characters in several Germanic alphabets that were used in northern Europe from ancient times until the adoption of the Latin alphabet. They have been found on stones and different household objects.

New study investigates the development of the Scandinavian gene pool over the latest 2000 years

A new study resolves the complex relations between geography, ancestry, and gene flow in Scandinavia – encompassing the Roman Age, the Viking Age, and later periods.

Researchers investigated a 2,000-year genetic transect through Scandinavia spanning the Iron Age to the present, based on 48 new and 249 published ancient genomes and genotypes from 16,638 modern individuals.

A surprising increase of variation during the Viking period indicates that gene flow into Scandinavia was especially intense during this period.

An international study coordinated from Stockholm and Reykjavik investigates the development of the Scandinavian gene pool over the latest 2000 years. In this effort the scientists relied on historic and prehistoric genomes, and from material excavated in Scandinavia.

These ancient genomes were compared with genomic data from 16,638 contemporary Scandinavians. As the geographical origin and the datings were known for all these individuals, it was possible to resolve the development of the gene pool to a level never realised previously.

Dr Ricardo Rodríguez Varela at the Centre for Palaeogenetics*, who analyzed all the data and extracted some of the ancient DNA used in the study, explains: “With this level of resolution we not only confirm the Viking Age migration.

We are also able to trace it to the east Baltic region, the British-Irish Isles and southern Europe. But not all parts of Scandinavia received the same amounts of gene flow from these areas. For example, while British-Irish ancestry became widespread in Scandinavia the eastern-Baltic ancestry mainly reached Gotland and central Sweden.”

The gene pool bounced back after the Viking period

Another new discovery in this study was what happened to the gene pool after the Viking period. The scientists were surprised to find that it bounced back in the direction of what it looked like before the Viking period migration.

Professor Anders Götherström at the Centre for Palaeogenetics, who is a senior scientist on the study, is intrigued: “Interestingly, the non-local ancestry peaks during the Viking period while being lower before and after.

The drop in current levels of external ancestry suggests that the Viking-period migrants got less children, or somehow contributed proportionally less to the gene pool than the people who were already in Scandinavia.”

Yet a new discovery was the history of the northern Scandinavian gene pool. There is a genetic component in northern Scandinavia that is rare in central and western Europe, and scientists were able to track this component in northern Scandinavia through the latest 1000 years.

Dr Ricardo Rodríguez Varela comments, “We suspected that there was a chronology to the northern Scandinavian gene pool, and it did indeed prove that a more recent influx of Uralic ancestry into Scandinavia define much of the northern gene pool. But if it is recent, it is comparatively so. For example, we know that this Uralic ancestry was present in northern Scandinavia as early as during the late Viking period”.

Based on well-known Swedish archaeological sites

The study is based on a number of well-known Swedish archaeological sites. For example, there are genomes from the 17th century warship Kronan, from the Viking and Vendel period boat burials in the lake Mälaren Valley, and from the migration period ring fortress Sandby borg on Öland.

Anders Götherström conclude: “We were working on a number of smaller studies on different archaeological sites. And at some point it just made sense to combine them into a larger study on the development of the Scandinavian gene pool.

The study, published today in Cell, is an international effort with several collaborators, but it was led by Dr Ricardo Rodríguez Varela and Professor Anders Götherstörm at Stockholm University, and Professor Agnar Helgason, and Kristjáan Moore at deCODE in Reykavijk.

The article “The genetic history of Scandinavia from the Roman Iron Age to the present” is published in Cell.

A large hall from the time of Viking Harald Bluetooth discovered

A large hall from the reign of King Harald Bluetooth of Norway was unearthed during housing construction work near Hune, a village in the Jammerbugt Municipality of North Jutland, Denmark.

The hall was up to 40 meters long and 8-10 meters wide, with 10-12 oak posts supporting the roof. They are rectangular in cross-section and measure up to 90×50 cm.

The hall probably served as a crucial location for political gatherings, for hosting visitors, and as the hub of social activity in the community’s social life.

Preliminary dating places the hall in the last half of the ninth century or the very first part of the eleventh century, but it was probably in use during the reign of Harald Bluetooth.

A rune stone near the excavation site has a date that fits this time frame. The stone, which dates from between 970 and 1020, is located in Hune Kirke and is inscribed with the words “Hove, Thorkild, and Thorbjrn set their father Runulv den Rdnilde’s stone.”

The hall’s design is reminiscent of structures found at Harald Bluetooth’s ring castles, including Fyrkat at Hobro and Aggersborg at Aggersund.

The researchers have only excavated a portion of the hall, but they believe that additional buildings and features lie beneath the surface to the east of the hall, as buildings of this type rarely stand alone.

Thomas Rune Knudsen, from North Jutland Museums said: “This is the largest Viking Age find of this nature in more than ten years, and we have not seen anything like it before here in North Jutland.”

Excavations will resume in the New Year, with a Carbon-14 analysis on organic remains for more accurate dating, the results of which are expected to be published by the end of 2023.

King Harald Bluetooth, a Viking-born king who turned his back on old Norse religion and converting to Christianity. He is noted for bringing Christianity to Denmark and earned the nickname Blåtand (meaning blue tooth) because of a dead tooth that is said to have been dark blue.

1,200-year-old Viking grave — with a shield and knives — found in a backyard in Norway

“This location has been a prominent hill, clearly visible in the terrain and with a great view,” says Marianne Bugge Kræmer to sciencenorway.no. She is an archaeologist at the Oslo Municipality Cultural Heritage Management Office.

Here, on the upper side of the small pond called Holmendammen, someone in the Viking Age chose to build a grave. Today it is a residential area in the west side of Oslo.

“The grave was located directly under a thin layer of topsoil and turf right on the east side of the highest point on the site, with a fantastic view west over today’s Holmendammen. This was a valley where the stream Holmenbekken flowed in ancient times,” Bugge Kræmer said to sciencenorway.no.

Was going to build a new detached house

Holmendammen was built at the beginning of the 20th century after the Holmenbekken was dammed, and the dam was used to make ice, according to lokalhistorewiki.no (link in Norwegian), a website with local history information.

Bugge Kræmer was in charge of the investigation of the Viking grave, which appeared as archaeologists were surveying the site. The investigation was triggered by plans to build new detached house on a plot by Holmendammen in the Vestre Aker district in Oslo.

Brooch from the Viking Age

The remains of a richly appointed Viking grave appeared here. Cremated human remains were uncovered, as well as many other objects.

The archaeologists found fragments of a soapstone vessel. There was also a penannular brooch – also known as a celtic brooch, a sickle, two knives, horse tack such as a possible bridle and a bell, Bugge Kræmer said. The discovery was first reported by NRK Oslo and Viken.

A shield boss was also discovered in the grave. This is the metal in the centre of a wooden shield. Since the wood disintegrates over the course of centuries, it is often the round shield boss that remains.

The penannular brooch in particular dates the grave to the Viking Age.

“For now, the grave has been dated based on the artefacts it contains. This type of brooch with spheres begins to appear in approximately AD 850 and became common after the 10th century AD,” Kræmer said to sciencenorway.no.

For the record, the Viking Age is defined as the period between around AD 800 to 1066.

This is a provisional dating, since the finds from the grave are in the Museum of Cultural History for conservation and further research.

But this buckle may say something about who was buried here.

Below you can see where Holmendammen is located in Oslo.

Gender and things

“This kind of cape brooch was used by men, and along with the discovery of a shield boss suggests that the deceased was a man,” Zanette Tsigaridas Glørstad said to sciencenorway.no.

Glørstad is an archaeologist and associate professor at the University of Oslo’s Museum of Cultural History. She is working with the Holmendammen find at the museum.

A great deal of information can be extracted from archaeological finds. Old DNA can be extracted from old bones and can, for example, reveal kinship, gender and other inherited characteristics. One striking example of this is a famous Viking grave in Birka in Sweden. For more than 150 years it was believed the person buried there was a male warrior, until researchers in 2017 did a genomic analysis which revealed that the remains in fact belonged to a woman.

But the remains from the grave at Holmendammen may not be able to be examined in this way.

“Right now the objects are in our conservation lab, and we are waiting for them to be ready before we can say anything more about the objects. We didn’t find any remains of unburnt bones, so we can’t extract DNA from what we found,” Glørstad said to sciencenorway.no.

It remains to be seen what information the researchers can uncover about the person who was buried here. A report on the discovery is now being prepared.

Oslo graves

Glørstad says this is the first artefact-rich Viking grave in Oslo that has been excavated by archaeologists. But many objects that can be linked to Viking graves have been found by, among others, construction workers in Oslo over the years.

Glørstad says that they are aware of the discovery of remains from around 60 graves from the Viking Age in Oslo. Most were found around the turn of the century in 1900 when the town expanded to St.Hanshaugen, Grünerløkka, Bjølsen, Tåsen and Sinsen.

These involve many individual items that can perhaps be connected to a grave, and in some cases they are found in a pile or together with burnt bones, says Glørstad.

For example, a Viking sword was found when Oslo’s new town hall was to be erected in the 1930s. This is just one of many discoveries that former county conservationist Frans-Arne Stylegar describes on this blog (in Norwegian), which Glørstad mentioned.

Medieval Woman’s Life-Sized Model Created in Norway

A life-size 3D model of a grinning old woman holding a walking stick looks like a contemporary elder on a stroll through her neighborhood. In reality, this woman lived nearly 800 years ago in Norway, and the model is a sculpted life-sized reconstruction based on her skeleton.

On Oct. 7, Ellen Grav, an archaeologist at the Norwegian University of Science and Technology (NTNU) University Museum, introduced the world to the lifelike model — named “Tora” — via Facebook. Tora’s likeness is now on display as part of an exhibitionat NTNU’s museum. (Tora’s name was selected in a public poll conducted by NRK, a Norwegian broadcast company.)

Tora was born near the end of the 1200s and lived in Trondheim, a city in central Norway. During that time, the medieval metropolis was growing rapidly and was inhabited by craftspeople and traders, according to the museum.

While there are no written records about Tora, archaeologists pieced together a story about this medieval woman’s life based on clues from her skeletal remains and where her body was exhumed.

“We know that she was buried in the churchyard near the street where the merchants lived,” Grav told Live Science in an email. “This suggests that she could have lived in a merchant’s family.”

Archaeologists suspect that the individuals who were buried in this churchyard were quite wealthy.

“Since Tora lived to be roughly 65, which is considered rather old for the period,” Grav said, “we do believe that she must have lived a somewhat good life for her time.”

A spinal deformity in Tora’s skeleton led Grav and her team to conclude that Tora likely walked hunched over. She also had no lower teeth and lived without them for a long period of time before her death. To the archaeologists, the bend in Tova’s back and her missing teeth hinted at “signs of hard work and lifelong wear on the skeleton,” Grav said.

Grav worked with Thomas Foldberg, a Denmark-based film industry makeup artist, to make Tora as lifelike as possible. Unlike many facial reconstructions that involve using either X-rays or CT scans, Foldberg focused on Tora’s skeleton to help create a 3D model of what this medieval woman may have looked like. For Tora’s skin, Foldberg used silicone and even “hand painted liver stains and other spots” on her body, Grav said.

“Every strand of hair in the eyebrows, lashes and facial hair is attached one by one,” Grav said. “It’s truly amazing artistic work.” 

For Tora’s costume, Marianne Vedeler, a textile professor in the Department of Archaeology at the University of Oslo in Norway, researched archeological finds from the area that dated to when Tora lived. Vedeler then tapped local dressmakers to fashion an outfit for the model.

“Nille Glæsel, an experienced dressmaker of Viking and medieval dresses [based in Norway], made Tora’s dress for us using medieval techniques,” Grav said. “She spun the yarn, weaved the fabric in and colored it with Rubia tinctorum [also known as rose madder]. Then she hand-sewed the dress after [Vedeler’s] reconstruction. She also made the shoes. We do have a lot of findings of shoes from Trondheim, so it was quite easy to know how the shoes should look.” 

As for Tora’s friendly expression, “it was very important for us to give the audience a feeling of a warm meeting, to better connect [them] with the medieval human,” Grav said.

“People always tend to think the medieval ages were dark and heavy, but there was also joy and happiness, people loved each other and some even lived a long life. Tora’s life was hard, but she must have had good days as well. I hope that people learn that they looked like us, had feelings like us and that they were people like us as well.”

Borgund: The Lost Viking Village Uncovered with 45,000 Artifacts Hidden in a Basement

In 1953, a parcel of land located close to the Borgund church on the west coast of Norway was going to be cleared, and a lot of debris ended up being discovered during the process. Fortunately, some people were able to identify the “debris” for what it actually was—items from the Norwegian Middle Ages.

An excavation was carried out the following summer. Archaeologists unearthed a large number of artefacts. The majority of them were put in a basement archive. After that, not much more transpired.

Now, some seven decades later, experts have begun the exhaustive work of analyzing the 45,000 objects that have been kept in storage for the purpose of gaining insight into a thousand-year-old Norwegian town with a shocking lack of historical knowledge. Medieval Borgund is mentioned in a few written sources, where it is referred to as one of the “little towns” (smaa kapstader) in Norway.

Professor Gitte Hansen, an archaeologist at the University Museum of Bergen, recently gave an interview with Science Norway in which she discussed what researchers have discovered about Borgund thus far. Danish archaeologist Gitte Hansen detailed that the construction of Borgund most likely took place at some point during the Viking Age.

“The story of Borgund begins sometime in the 900s or 1000s. Fast forward a few hundred years and this was the largest town along the coast of Norway between Trondheim and Bergen. Activity in Borgund may have been at its most extensive in the 13th century. In 1349, the Black Death comes to Norway. Then the climate gets colder. Towards the end of the 14th century, the town of Borgund slowly disappeared from history. In the end, it disappeared completely and was forgotten.” – Science Norway reports.

Professor Hansen is currently researching the artefacts in collaboration with researchers from Germany, Finland, Iceland, and the United States. The project has previously received financial support from the Research Council of Norway and contributions from several other research institutions in Norway.

Researchers specializing in different areas, such as textiles and the old Norse language, have been brought together to form a team. Scientists are able to gain knowledge about the clothing worn during the Viking Age by analyzing textiles that were discovered in Borgund.

Shoe soles, pieces of cloth, slag (the by-product of smelting ores and used metals), and potsherds were among the priceless artefacts discovered by the archaeology team led by Asbjørn Herteig during excavations of the long-lost Viking village of Borgund.

According to Professor Hansen, these artefacts can tell a great deal about how Vikings lived on a day-to-day basis. A significant number of the Viking artefacts are still well-preserved and may be scrutinized in great detail. The basement may contain as many as 250 separate pieces of clothing and other textiles.

“A Borgund garment from the Viking Age can be made up of as many as eight different textiles,” Professor Hansen explained.

According to Science Norway, in the remains of Borgund down in the basement under the museum in Bergen, researchers are now discovering ceramics from almost all of Europe. “We see a lot of English, German and French tableware,” Hansen says.

People who lived in Borgund may have been in Lübeck, Paris, and London. From here they may have brought back art, music, and perhaps inspiration for costumes. The town of Borgund was probably at its richest in the 13th century.

“Pots and tableware made of ceramic and soapstone from Borgund are such exciting finds that we have a research fellow in the process of specializing only in this,” Hansen says. “We hope to learn something about eating habits and dining etiquette here on the outskirts of Europe by looking at how people made and served food and drink.”

The study of the Borgund artefacts has already produced results and Professor Hanse says “there are many indications that people here had direct or indirect contact with people across large parts of Europe.”

In addition, researchers have found evidence that inhabitants of the Viking village of Borgund enjoyed eating fish. For the people of Borgund, fishing was essential.

It is still unknown, though, whether they transported fish to the German Hanseatic League in Bergen or exchanged fish with other regions of Norway and Europe.

Scientists found “a lot of fishing gear. This suggests that people in Borgund themselves may have fished a lot. A rich cod fishery in the Borgundfjord may have been very important for them,” Hansen says.

We might infer from the ironwork remnants that the forgotten town in Western Norway had a strong foundation. Perhaps blacksmiths played a particularly significant role in this town.

And why exactly did Asbjørn Herteig and his associates discover a significant amount of waste materials from shoemakers? Up to 340 shoe fragments can provide information on shoe style and the preferred types of leather used for shoes throughout the Viking Age.

Our knowledge of Borgund from the historians’ written sources is rather limited. Because of this, the role of archaeologists and other researchers in this specific project is crucial.

There is, however, one significant historical source. It is a royal decree from 1384 which obliges the farmers of Sunnmøre to buy their goods in the market town of Borgund (kaupstaden Borgund).

“This is how we know that Borgund was considered a town at the time,” Professor Hansen says. “This order can also be interpreted as Borgund struggling to keep going as a trading place in the years after the Black Death in the middle of the 14th century.” And then the city was forgotten.

Possible Medieval Shipwreck Spotted in Norway Lake

“Mjøsa is like a mini-ocean, or a really large fjord,” says marine archaeologist Øyvind Ødegård from NTNU. For centuries, ships and boats have travelled these waters. Diving archaeologists have registered around 20 wrecks in shallow water. But the lake has never been examined beyond scuba diving depth of around 20-30 metres.

“We believed that the chance of finding a shipwreck was quite high, and sure enough, a ship turned up,” Ødegård says.

The mapping of the sea bottom of Mjøsa started a couple of weeks ago. It yielded results on the very last day. At 410 metres, the autonomous underwater vehicle Hugin from the Norwegian Defence Research Establishment found a shipwreck.

Possibly a medieval shipwreck

The ship is about ten metres long – it’s possible that it originally was a bit longer – and 2,5 metres wide. This places it somewhere in between the categories of a large boat or a ship, according to Ødegård.

At one end, it looks as though the strakes are no longer fastened properly to the ship, which indicates that the iron nails fastening them have probably begun to rust and disintegrate.

“This tells us that the ship has probably been at the bottom of Mjøsa for a while,” Ødegård says.

The Norwegian newspaper VG excitedly announced for a brief time that the archaeologists had discovered a Viking ship, but this is not the case.

Ødegård explains that Viking ships usually have the steering oar on the side of the ship. During the Middle Ages, the steering oar was rather placed right at the back of the ship – and judging by the images obtained, this is what the shipwreck in question has.

“If this is correct, it is highly likely that the ship is not older than from the 1300s,” Ødegård says.

The ship is clinker built, a Nordic tradition of ship building also known from the Viking ships and listed on the UNESCO list of Intangible Cultural Heritage.

“This tradition is recognized as a very important part of our cultural heritage,” says Ødegård.

Naval battles and trade routes

The Norwegian Defence Research Establishment was given the task of mapping Mjøsa by The Norwegian Environment Agency. The job was to find possible explosives and ammunition that may have been dumped in the lake by an ammunition factory which is said to have done so between the 1940s and up until the 70s. Researchers from NTNU had simultaneously started up a project about Mjøsa, and so a collaboration came about.

“We realized that the entire lake is more or less unknown territory,” says Ødegård.

NTNU has therefore started up a research project about Mjøsa starting next year, which will go on for about five years.

Vice principle for NTNU, in Gjøvik, Gro Dæhlin, says to the newspaper VG that Mjøsa is a treasure trove for old ships.

Director of Mjøsmuseet, Arne Julsrud Berg, is also very excited about the find.

He tells VG that there were huge naval battles on Mjøsa in the 1100s and 1200s, when large fleets including ships the size of the famous Gokstad Viking ship met in battle on the water.

“Even during the Viking Age there were huge sea battles on Mjøsa,” Berg says to VG.

The areas surrounding Mjøsa were wealthy farm areas, and goods have been transported across Mjøsa to and from Oslo throughout the centuries.

More to come

Raising the ship would probably pose a very complex task.

“I don’t know if that has ever been done with robots,” says Ødegård.

On Thursday evening this week, having discovered the shipwreck in the sonar images from FFI, Ødegård and the team went out to try and get better images with a different robot, but the waters were too rough.

“What we want to do now is to get data from cameras and other sensors. We can blow away some sand from sediments with the propels on the robot, and we can use manipulator arms, but it will be what we call a non-intrusive investigation at first,” says Ødegård.

The two-week mapping only covered around 40 square kilometres of the 360 sqare kilometre large lake. More ships may turn up – within the next few days, when the researchers analyse more of the data collected, or sometime during next spring, when the next field trip will take place.

“Because this is a freshwater lake, the wood in such a ship is preserved. The metal may rust, and the ship may lose its structure, but the wood is intact. A similar ship to the one we now found, would not have survived for more than a few decades if it had gone down on the coast,” Ødegård says.

“So if we are going to find a Viking shipwreck in Norway, then Mjøsa is probably the place with the most potential for such a find,” he says.

Large-Scale Trade in Herring Dates to the Viking Age

Historians have believed extensive herring trade started around the year 1200 AD, later controlled by the Hanseatic League. Now, a new study shows that it was already established in the Viking Age.

“We found that this trade existed already around 800 AD, 400 years earlier, which really pushes back this extensive fishing,” says Doctoral Research Fellow Lane Atmore at the University of Oslo.

She is the first author of the study, published today in PNAS, which shows that herring bones from western populations around Sweden and Denmark were found as far east in the Baltic as Truso in today´s Poland. Truso is known as an important Viking Age trade port.

“In the genetic signature from these bones, we found that the fishes were adapted to higher salinity than you find in the central Baltic. This means they were coming from around Kattegat, and then they were being shipped into the eastern Baltic,” Atmore says.

The lower salinity of The Baltic Sea means that herring from the population in Kattegat will have a hard time adapting to the waters further east.

“That high salinity adapted fish are never found that far in,” Atmore says.

More difficult to trade

Her co-author, Associate Professor Bastiaan Star, has previously studied cod trade in the same area.

“Earlier we have seen that cod from the trading place Hedeby in what is now Germany had travelled all the way from northern Norway. Our new study shows that it was not just cod. It was also herring, a fish that technologically is much more difficult to trade,” Star says.

Atlantic herring (Clupea harengus) is a much fattier fish than cod and not easy to store, let alone trade if you don’t have the right technology.

“If you don’t cure it with salt or smoke, it will go bad very quickly. You need access to salt and wood so that you can cure it and then ship it. You need to have extensive trade networks and to catch enough fish if it´s going to be worth the investment,” Atmore says.

“I think that fish was traded over greater distances than previously anticipated. We can now pin down this date because these bones are absolutely dated between 800 and 850,” Star says.

“We can´t prove that it was the Vikings who brought the herring from one place to the next, but we know that we have herring bone from a site where Vikings were trading,” Atmore says.

Biology and archaeology

Atmore and Star are both biologists. In this study, they have worked closely with archaeologists. One of them is Professor James H. Barrett at NTNU University Museum.

“The herring industry of the Baltic Sea supported one of the most important trades in medieval Europe,” Barrett says.

“By combining the genetic study of archaeological and modern samples of herring bone, one can discover the earliest known evidence for the growth of long-range trade in herring, from comparatively saline waters of the western Baltic to the Viking Age trading site of Truso in north-east Poland,” Barrett says.

The study also reveals what has happened to the herring populations in more recent times.

“The economic and political ramifications of the herring industry are well-charted, but its ecological impacts have been much debated,” Barrett says.

Spring spawners and autumn spawners

The different populations of herring have their own spawning grounds, hence their adaptation to different levels of salinity. Populations also differ in spawning season.

“There are two major populations that spread across all Atlantic herring. One spawns in the springtime, and one spawns in the autumn. These populations spawn in unique locations and in different seasons, so they don’t interbreed much. This means they are genetically different from each other,” Atmore explains.

She is now able to identify where these fish are coming from to see how populations grow and decline, and how this is impacted by the fishing industry.

“We found that earlier in the historical record, starting around 800, you get more fish in these archaeological sites that come from the autumn spawning population in the western Baltic. This is a population that was targeted by a famous fishery around 1200,” Atmore says.

Collapsed 100 years ago

In more recent times it was the opposite.

“They were then targeting the autumn spawners and this population collapsed in the 1920s. In the Baltic now commercial catches are 90% spring spawners,” Atmore says.

“It´s not that the autumn spawners entirely disappear in the Baltic. It is more that they are not commercially interesting anymore. They are still there, but not in the numbers we were used to,” Star says.

He is not in doubt that the fishing industry had a major impact on the herring populations.

“There is a consistent pattern with over exploitation that takes place over centuries,” Star says.

“Our results provide a new and persuasive way to test the archaeological hypothesis that human impacts on super-abundant European marine fish started already in the Middle Ages, and that different herring stocks were targeted sequentially through time,” Barrett says.

This also means that the ecology of the Baltic Sea has shifted. Autumn spawners spawn in a different place at a different season.

“They are also bigger than the spring spawners and they eat slightly different food. When the population of autumn spawners goes far down in size, the ecology is going to change,” Atmore says.

“The Baltic Sea is much more confined compared to the North Sea. Some of the impacts that humans or climate may have, is amplified in such a small system,” says Star.