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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.

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Presentation on theme: "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."— Presentation transcript:

1 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

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3 Limfjorden

4 Salinity 5000BP - 1990s.

5 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

6 Baselines c. 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.

7 Lif Jacobsen The 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

8 Growing fishing effort, 1890- 1925 Due to the increasing number of: Fulltime fishermen. Motor driven boats (from 1905) Amount of fishing gear. ( standing gear )

9 Relationship between effort, cost and yield. The interrelationship between the various objectives. Source: Cunningham m.f.: Fisheries Economics an introduction.p.118. 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) f oa, (bio economical equilibrium) reached by 1921. MSY, (maximum sustainable yield): ?

10 Baselines c. 1825-1850s Period of transition Commercial fishery –Herring collapse –Eel crisis –Whitefish disappears –Emergence of plaice –Emergence of Aurelia Invention of Danish seine

11 Limfjorden

12 North Sea breach in 1825

13 Baselines c. 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

14 400 years of catching herring

15 Time series of fishing effort Pound nets

16 Pound nets 1752-1862

17 Beach seines

18 Seines in different areas

19 Gill nets

20 Eksport af å l

21 Bundgarn til helt

22 Cpue whitefish

23 Social consequences

24 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


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