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“It moves as you go...” baselines in Limfjorden environmental history DK INCOFISH unit: Poul Holm Bo Poulsen Anne H. Marboe Department of History and Social Theory University of Roskilde INCOFISH, WP2 Workshop Tallin, 3 March 2006 Limfjorden Salinity 5000BP - 1990s.

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it moves as you go baselines in limfjorden environmental history

“It moves as you go...” baselines in Limfjorden environmental history

DK INCOFISH unit:

Poul Holm

Bo Poulsen

Anne H. Marboe

Department of History and Social Theory

University of Roskilde

INCOFISH, WP2 Workshop Tallin, 3 March 2006

limfjord baselines c 1980 2006
Limfjord baselines c. 1980-2006
  • Mussel scraping
  • Suffering from depletion of grounds
  • Mussel & oyster farming
  • No other commercial fishery
  • Some angling

Data: gov. Statistics, ongoing sci. surveys

baselines c 1860 1980
Baselinesc. 1860-1980
  • Commercial fishing for
    • Eel
    • Plaice
    • Herring
  • Cradle of modern Danish fishing
    • Most important fishing area in DK until c. 1900
  • Regime shift c. 1980
  • Data: gov. Stats., pioneering mar. Bio. In 19th c.
slide7

Lif JacobsenThe Limfjord fishery: Economic and ecological explanations for the collapse of the 1920´s

Key events in the Limfjord fishery (1890-1925):

1888 First national Fishery Law

Introduction of motor driven boats in the

fisheries around 1905.

Increasing number of fishermen.

Increasing amount of fishing gear.

1923/25 Legislation of motor driven winches for

pulling seines onboard.

Focus on the main species:

Eel, plaice, cod and herring

Based on:

The Danish Annual Fishing Report 1888-1921

Copy of The Fishing Controls correspondence, etc

Reports from The Danish Biological Station etch

growing fishing effort 1890 1925
Growing fishing effort, 1890-1925
  • Due to the increasing number of:
  • Fulltime fishermen.
  • Motor driven boats (from 1905)
  • Amount of fishing gear. (“standing gear”)
relationship between effort cost and yield
Relationship between effort, cost and yield.

TC, (total cost) and Effort continually increasing.

SMEY, (static maximum economic yield) reached by 1895.

TR, (total revenue) become smaller due to a negative development in prices (from 1917)

foa, (bio economical equilibrium) reached by 1921.

MSY, (maximum sustainable yield): ?

The interrelationship between the various objectives.

Source: Cunningham m.f.: Fisheries Economics an introduction.p.118.

baselines c 1825 1850s
Baselinesc. 1825-1850s
  • Period of transition
  • Commercial fishery
    • Herring collapse
    • Eel crisis
    • Whitefish disappears
    • Emergence of plaice
    • Emergence of Aurelia
  • Invention of Danish seine
baselines c 1600 1825
Baselinesc. 1600-1825
  • Phases of very large herring fisheries
  • Also commercial fisheries for:
    • Eel (Anguilla anguilla)
    • Whitefish, (Coregonus lavaretus)

Data: pre-stat. era; but proxy data from historical archives

baseline s report
Baseline(s) report
  • ‘Same’ water - very different ecosystems over 4 centuries
  • Causes of change? Depending on baseline
      • Regime shifts
      • Fishing mortality
      • Climate change
      • Hydrographic change
      • Episodic events
      • Societal changes