Ancient bones found around the Strait of Gibraltar suggest that the Romans might have had a thriving whaling industry, researchers have claimed.
The bones, dating to the first few centuries AD or earlier, belong to grey whales and North Atlantic right whales – coastal migratory species that are no longer found in European waters.
Researchers say this not only suggests these whales might have been common around the entrance to the Mediterranean in Roman times, but that Romans might have hunted them.
They add that Romans would not have had the technology to hunt whale species found in the region today - sperm or fin whales which live further out at sea - meaning evidence of whaling might not have been something archaeologists and historians were looking out for.
“It’s the coastal [species] that makes all the difference,” said Dr Ana Rodrigues, first author of the research from the Functional and Evolutionary Ecology Centre, CEFE, in France.
The right whale was once widespread in the North Atlantic, with breeding grounds off the northern coast of Spain and north west Africa, but was hunted by Medieval Basque whalers among others, and are now only found in the Western North Atlantic. Grey whales disappeared from the North Atlantic some time in the 18th century, and are now only found in the Pacific.
Until the recent discoveries it was unclear whether the whales’ habitat had ever included the Mediterranean: the region is southerly enough for the animals to potentially calve there after feeding in more northerly areas. While there are a handful of historical reports of right whales cropping up in the Mediterranean, the only reliable grey whale sighting in the region was in 2010 and is thought to have been a misguided individual that turned up from the Pacific.
Writing in the journal Proceedings of the Royal Society B, Rodrigues and a team of archaeologists and ecologists, describe how they set out to unpick the issue by examining 10 bones – thought to be from whales – collected during recent archaeological digs or housed in museum collections. These bones came from five sites – four around the Strait of Gibraltar and one site on the coast of north-west Spain, three of which were linked to the Roman fish-salting and fish-sauce making industries.
The team combined previous anatomical analysis with new analyses based both on DNA extracted from the bones and their collagen – a protein whose makeup differs between groups of species, and which degrades more slowly than DNA.
While one of the bones was found to be from a dolphin and another from an elephant – possibly a war animal – three were identified as grey whales, and two as North Atlantic right whales with another also suspected of being from this latter species. All were found by carbon-dating as being from either Roman or pre-Roman times – findings backed up by dating based on information from the archaeological sites.
The team say the discovery suggests grey and North Atlantic right whales were common in the waters around the Strait of Gibraltar during Roman times, since whale bones rarely end up in the archaeological record and they are not prized possessions.
This theory is backed up by writings from the time: Pliny the Elder – a fervent naturalist who died down the coast from Pompeii during the volcanic disaster – appears to reference whales calving in the coastal waters off Cadiz in the winter in his Naturalis Historia. And if the whales were present, the team say, it is possible the Romans hunted them.
The team say the location of the bones, and other evidence, suggests whales might even have entered further into the Mediterranean sea itself to calve.
Dr Vicki Szabo, an expert in whaling history from Western Carolina University said the study offered a rare glimpse into the past habitats of the whales, and backed up ideas that industrial hunting might have happened far earlier than widely thought, although its scale is unclear. “Whales are considered archaeologically invisible because so few bones are transported from shore to site, so I think in that context this concentration of species that they have is meaningful,” she said.
Mark Robinson, professor of environmental archaeology at the University of Oxford, said there have been suggestions for a decade that some Roman sites with fish vats in the region might have been linked to whaling. “The Greek author Oppian, writing in the 2nd century AD, describes whales being hunted in the Western Mediterranean by harpooning them on the surface, also using tridents and axes to kill them, lashing them to a boats and then dragging them to the shore.”
However Dr Erica Rowan, a classical archaeologist at Royal Holloway, University of London, said while the study suggests the habitats of the whales probably extended to include the Gibraltar region, how common the whales were and whether the Romans industrially hunted them as they did fish such as tuna remains unclear – not least because the study included just a handful of bones from a period spanning several hundred years.
“I think that if these whales were present in such numbers and were being caught on an industrial scale that we would have more evidence, perhaps not in the zoo archaeological record but in the ceramic record and in the literary sources,” she said. “The Romans ate and talked about an enormous variety of fish and seafood, and if whale was widely exploited and exported, then it is strangely absent from many discussions.”
But Rodrigues is more hopeful about what the discovery tells us. “I think [this study] can change our perspective of the Roman economy,” she said.