The Prehistory of Intensive Sea Fishing Dr. James Barrett McDonald Institute for Archaeological Research

Why Study the Early Development of Sea Fishing? Implications for social and economic history Implications for historical ecology

To dispel two opposing popular misconceptions: ‘modernity’ and the ‘static past’ To introduce the archaeological study of fishing To illuminate the early growth of intensive sea fishing in Northern and Western Europe – focusing on cod as a case study To introduce efforts to detect any associated early impacts on marine ecosystems Today’s Objectives

In the Beginning … The Mesolithic

Stable Carbon Isotopes Show Changing Dietary Importance of Marine Protein

High Reliance on Marine Protein Doesn’t Reappear until the Middle Ages

Scandinavia: The Exception to the Rule? Catching and eating cod, herring and related species part of daily routine throughout prehistory

Sea Fishing in Atlantic Scotland Very little fishing before the Viking Age Intensification in the 9 th & 11 th centuries

Base of Viking Age midden Top of marine zone Quoygrew Chronology Base of marine zone 10 th century 11 th – 12 th century

The Fish Middens of Atlantic Scotland Robert’s Haven St Boniface Quoygrew

Dried Cod Production Decapitation Removing the anterior vertebrae Based on cut marks and element distributions Similar cut marks occur on possible imported specimens around the Baltic and North Seas. ‘Stockfish’ trade?

England Very little sea fishing until near the end of the first millennium Rapid expansion of cod and herring fishing within a few decades of AD 1000 – the fish event horizon Continued intensification over the long term, with increasing diversity of species exploited and expansion to new fishing grounds (e.g. Iceland and Newfoundland)

a)

The York Sequence n=13517, derived from sieving only

York: Butchered Cod Vertebrae Transverse cuts: typically used as evidence of stockfish production, caused when severing the vertebral column to remove the head and anterior vertebrae

Belgium: 11 th Century: Flatfish & Herring 12 th Century: Whiting & Haddock 13 th Century: Cod

Ribe, Jutland, Denmark: Cod Size Distribution by Date

Poland: 10 th -11 th Century: Herring 13 th -14 th Century: Cod Estonia: 13 th -14 th Century: Cod Eastern Sweden: 8 th Century: Herring 13 th Century: Cod

Cod Provenance: Control Samples Possible to distinguish approximate location of catch using reliable stable isotope analyses

Causal Variables Temperature Salinity Length and type of food web in each area, and consequent trophic level of cod temp salinity TL

Cod Provenance: Target Samples Arctic Norwegian cod at Hedeby (9 th -11 th century)? Traded cod at Wharram Percy (13 th century)? Local dried cod production in the Baltic (15 th century)

Uppsala, Sweden: 13 th Century Vertebrae All appear to be imports from Arctic Norway or the North Sea

Uppsala, Sweden: 14 th -15 th Century All but one specimen appear local

Poland: 13 th -14 th Century Vertebrae All appear to be imports, perhaps from Arctic Norway

All but one specimen appear local Poland: 14th-15th Century

Estonia: Late 13 th -14 th Century All appear to be imports, perhaps from the North Sea

Commercial Fishing: Potential ‘Drivers’ ‘Socio-economic’: The Viking Age diaspora Rapid urban expansion The development of long- range trade in staple goods (cf. ship capacities) Changes in Christian fasting practices (e.g. the Benedictine reform of c.970) ‘Environmental’: The Medieval Warm Period (increased agricultural production & population) Human impacts on freshwater ecosystems The MWP may also have increased cod & herring abundance in northern fishing grounds – a Butterfly Effect

But can we detect the impact of this early commercial fishery on marine ecosystems?

Bait Collection at Quoygrew, Orkney

Robert’s Haven: Saithe

Downward shift in trophic level between past and present? Eutrophication of S. North Sea evident in Middle Ages? S. North Sea Modern δ15N N. North Sea Modern δ15N Long Term Human Impacts? A North Sea Example

Acknowledgements Leverhulme Trust Historic Scotland British Academy Census of Marine Life English Heritage Heritage Lottery Fund History of Marine Animal Populations McDonald Institute for Archaeological Research Social Sciences and Humanities Research Council of Canada Society for Medieval Archaeology York Archaeological Trust Project collaborators: especially Jennifer Harland, Cluny Johnstone, Anton Ervynck, Michael Richards and Wim Van Neer