Historical sources show that the expansion of cod fishing from the 15th century onward played in important role in European colonisation of the North-West Atlantic. It is also known that fishing was important earlier in the medieval period, but the records usually go back no further than the 12th century at the earliest. By then, sea fishing was a major industry in many parts of Northern Europe – but when did it start? Only archaeology, it seems, can answer that question.
Virtually all catches from the 7th to the 10th centuries were dominated by freshwater and migratory species (particularly carp family species and eels). By contrast, most 11th century and later catches had far higher proportions of herring and/or cod, while in the 13th to 16th centuries, some assemblages were dominated by cod. It is the change in the 11th and 12th centuries – before relevant historical records are available – that seems to be the big one.
Various explanations for this change have been put forward: environmental – the fall in agricultural output spurred a search for new foood supplies, or a decline in freshwater fish-stocks pushed the industry towards sea fishing; cultural – Christian fasting determined the demand for more fish; or technological – the introduction of floating driftnets.
However, there is also a possible economical explanation. Richard Hodges published his seminal study Dark Age Economics in 1982, postulating the connection of a series of changes in the economy of North-West Europe: from the exchange of high-value prestige goods to that of low-value staples; from gift exchange to market transactions; and from proto-urban settlements to real towns. He dated these changes to the 10th and 11th centuries. Although aspects of this interpretation have been challenged, what was lacking, until now, was archaeological analysis of the evidence.
Studies of modern-day fish tissue have shown that it carries an ‘isotopic signature’ – a chemical indication of what the fish have been eating and of the temperature and salinity of their marine environment – which has enabled scientists to distinguish between different populations of the same fish species. In medieval times, cod were usually decapitated prior to drying and salting for long-distance trade. This means that cod skulls, when found archaeologically, are usually local. Vertebrae, on the other hand, especially if they bear tell-tale butchery marks, are likely to be from cod that were sold and eaten. By cross-referencing the isotopic signatures of cod skulls and vertebrae from different sites, the heads and bodies can be matched up across hundreds of miles.
Under the direction of James Barrett, Deputy Director of the McDonald Institute for Archaeological Research, Cambridge, samples were collected from sites around Artic Norway, the North Sea, the Kattegat, and the Baltic. With clear references to regional differences, the Cambridge-led team revealed that cod had, indeed, been traded – sometimes over extremely long distances.
‘This could mark the origins of Europe as an economic community,’ comments Barrett. ‘Earlier European communities traded small quantities of luxury items over long distances, but fish are high in bulk and low in value. The explosion of the fish trade in Northern Europe during the 11th century therefore implies a thriving network of commercial links – and perhaps the first steps towards a European identity.'
For the full article, see Current Archaeology 221