The Leverhulme Trust

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 9th & 11th centuries

Base of Viking Age midden

Top of marine zone

Quoygrew Chronology

Base of marine zone10th century

11th – 12th 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)

10-1

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Component 2

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Flatfish

Cyprinid Pike

Smelt

'Gadid'

Eel

Salmonid

Herring

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a)

The York Sequence

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s/ea

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Clupeidae

Cod

Haddock

Pleuronectidae

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Cyprinidae

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:

•11th Century: Flatfish & Herring

•12th Century: Whiting & Haddock

•13th Century: Cod

Ribe, Jutland, Denmark:Cod Size Distribution by Date

Poland:

•10th-11th Century: Herring

•13th-14th Century: Cod

Estonia:

•13th-14th Century: Cod

Eastern Sweden:

•8th Century: Herring

•13th Century: Cod

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δ13C

δ15N

Arctic Norway

Northern NorthSea

Southern andCentral North Sea

Kattegat

Eastern Baltic Sea

Cod Provenance: Control Samples

• Possible to distinguish approximate location of catch using reliable stable isotope analyses

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δ13C

δ15N

Arctic Norway

Northern NorthSea

Southern andCentral North Sea

Kattegat

Eastern Baltic Sea

Causal Variables

• Temperature• Salinity • Length and type

of food web in each area, and consequent trophic level of cod temp

salinity

salinity

TL

TL

Cod Provenance: Target Samples

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δ13C

δ15N

WharramPercy

MalaNieszawka

Haithabu

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

Uppsala, Sweden:13th Century Vertebrae

• All appear to be imports from Arctic Norway or the North Sea

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δ15N

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Uppsala, Sweden: 14th-15th Century

• All but one specimen appear local

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Uppsala Late Cranial l

Uppsala Late Cleithra x

Poland: 13th-14th Century Vertebrae

• All appear to be imports, perhaps from Arctic Norway

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δ13C ‰

δ15N

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• All but one specimen appear local

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δ13C ‰

δ15N

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Poland Late Vertebrae x

Poland Late Cranial l

Poland Late Cranial xl

Poland Late Cleithra l

Poland Late Cleithra x

Poland: 14th-15th Century

Estonia: Late 13th-14th Century

• All appear to be imports, perhaps from the North Sea

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δ13C ‰

δ15N

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Estonia Vetrebrae l

Estonia Vertebrae x

Estonia Vertebrae xx

Estonia Cleithra x

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

25 50 75 100 125

Saithe Total Length (cm)

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11th-13th/14th Century 14th-16th Century

25 50 75 100 125

Saithe Total Length (cm)

• Downward shift in trophic level between past and present?• Eutrophication of S. North Sea evident in Middle Ages?

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δ13C

δ15N

S. North SeaModern δ15N

N. North SeaModern 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