“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

400 years of catching herring

catches of herring, 1600-1999

0

2.000

4.000

6.000

8.000

10.000

12.000

14.000

16.000

18.000

1600 1625 1673 1698 1721 1746 1794 1819 1842 1867 1890 1915 1940 1963 1988

ton

nes

Time series of fishing effort

Pound nets

Pound nets 1752-1862

Number of pound nets for spring fishery at Nørlå and Fruens Grund, both at Nibe

0

100

200

300

400

500

600

700

800

900

1755 1760 1765 1770 1775 1780 1785 1790 1795 1800 1805 1809 1814 1819 1824 1829 1834 1839 1844 1849 1854 1859

Beach seines

Seines in different areasSeines in Kær County, 1779-1852

12

14

13 13 13

0 0

4 4

0

2

4

6

8

10

12

14

16

1770 1775 1780 1785 1790 1795 1800 1805 1810 1815 1820 1825 1830 1835 1840 1845 1850

Seines at Løgstør, 1801-1851.

0

2

4

6

8

10

12

14

16

18

20

år 1805 1810 1815 1820 1825 1830 1835 1840 1845 1850

Gill nets

Number of gillnet boats from Gjøl to Hals, 1741-1841.

275

147137

99

187

220

355

46

00

50

100

150

200

250

300

350

400

1740 1750 1760 1770 1780 1790 1800 1810 1820 1830 1840 1850 1860 1870

Eksport af ål

Ål udført fra Aalborg, 1801-1845.

87,7

45,4

36,7

13,316,0

3,88,3

2,61,2 2,1 0 0,6 0 0 1,7

8,4

0

10

20

30

40

50

60

70

80

90

100

1800 1805 1810 1815 1820 1825 1830 1835 1840 1845

ton

s

Bundgarn til helt

Cpue whitefish

Fangst pr. indsats i Østerild-, Tømmerby- og Mellem Fjorde samt Hovsør Havn, 1812-29.

0

200

400

600

800

1000

1200

1400

1812 1814 1816 1818 1820 1822 1824 1826 1828 1830 1832

An

tal h

elt

pr.

bu

nd

gar

n

Social consequences

antal beskæftigede ved de vigtigste limfjordsfiskerier, 1820-1860

0

1000

2000

3000

4000

5000

1820 1840 1860cirka tidspunkt

anta

l bes

kæft

iged

e

sild ål helt rødspætter

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