“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 QuickTime™ and a TIFF (Uncompressed) decompr are needed to see this pi QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.
24
Embed
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.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
“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
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Limfjorden
Salinity 5000BP - 1990s.
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
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.
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 1888-1921Copy of The Fishing Controls correspondence, etcReports from The Danish Biological Station etch
Growing fishing effort, 1890-
1925 • Due to the increasing
number of:
• Fulltime fishermen.• Motor driven boats
(from 1905)• Amount of fishing
gear. (“standing gear”)
Value of fishing gear primarily used for catching herring, eel, plaice and cod.
0
200.000
400.000
600.000
800.000
1.000.000
1.200.000
1891 1895 1900 1905 1911 1916 1921
Kr.
i 19
14-p
rice
Relationship between effort, cost and yield.
The interrelationship between the various objectives.Source: Cunningham m.f.: Fisheries Economics an introduction.p.118.
Outcome of investment, 1891-1930.
0
0,5
1
1,5
2
2,5
3
1891 1895 1900 1905 1911 1916 1921 1925 1930
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): ?
Baselinesc. 1825-1850s
• Period of transition• Commercial fishery
– Herring collapse– Eel crisis– Whitefish disappears– Emergence of plaice– Emergence of Aurelia
• Invention of Danish seine
Limfjorden
North Sea breach in 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