Debriefing FishBanks
An example of game debriefing
Dennis Meadows
Uppsala University; 11/5/2015
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
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Reflecting on the Game
• Video of an actual fishing system
(optional)
• Performance of the teams
• Alternative strategies
• Why did that happen?
• What can be done?
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
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Summary of Game Behavior
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9
8
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D
E
X
7
6
5
4
3
2
1
0
1
2
3
4
5
6
7
8
9
10
YEAR
FISH
FISH
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BOATS
SHIPS
CAT CH
CATCH
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Typical Game Behavior
Fish
Catch
Ships
0
1
2
3
4
5
6
7
YEAR
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Typical Game Behavior - Fleet
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
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Typical Game Behavior - Catch
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Typical Game Behavior - Fish Population
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Does fish depletion happen in real life?
• Pacific sardine fishery
• Peruvian anchovy
fishery
• North Sea Herring
• Georges Bank Cod
fish
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Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
1988
1984
1980
1976
1972
1968
1964
1960
1956
1952
1948
1944
1940
1936
1932
1928
1924
1920
1916
Catch (th ousand tons)
Pacific Sardine Catch
700
600
500
400
300
200
100
0
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Peruvian Anchovy Catch
14
12
CATCH (Million s o f Ton s)
10
Estim ated Maxim um Sustainable Catch
8
6
4
2
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
1966
1964
1962
1960
0
YEAR
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North Sea Herring Catch
Mark Wise, Common Fisheries Policy of the European Community, New York, Methuen, 1984.
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Georges Bank Codfish Catch
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Total World Fish Catch
90
CATCH (Millions of Tons)
80
70
60
50
40
30
20
10
1993
1991
1989
1987
1985
1983
1981
1979
1977
1975
1973
1971
1969
1967
1965
0
YEAR
Source: Fisheries of the United States.
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
US Dept. of Commerce.
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Global Fisheries Depletion
Thousands of Tons
Region
Species
Potential
Northwest Atlantic
Cod
Haddock
Capelin
Herring
1,350
100
500
300
643
36
110
284
707
64
390
16
Northeast Atlantic
Herring
2,250
1394
856
Southeast Atlantic
Pilchard
600
66
534
Northwest Pacific
Salmon
350
258
92
Northeast Pacific
Halibut
Perch
King Crab
38
210
40
43
33
10
-5
177
30
Southeast Pacific
Anchoveta
2-5,000*
2,877
2,123
10,738
5754
4,984
Total
1988 Catch
Loss
Source: United Nations Food and Agriculture Organization, "Review of World Fishery Resources," Rome 1990.
*Potential use to be 9,-11,000,000 tons before the collapse in the 1960s. The new potential is more likely 25,000,000 tons, but the stock is highly variable.
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
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New England Fisheries - Hard Times
 I remember catching 5,000 pounds of fish in eight
nets. Today, it might take up to 80 nets. Back then, the
average codfish in the spring would probably be 25 to
40 pounds. Now, it's 5 to 8 pounds." - Peter Morse
"Go down to the docks and talk to the guys down
there," said John Nelson, chief of the Marine Fisheries
Division of the state Fish and Game Department.
"Most of them have their boats for sale. If they could
sell their boats and do something else, they
 would.
Source: Clare Kittredge, "N.H. Fish Story Is Not a Happy One," Boston Globe. February 4, 1990.
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
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Present Value of the Fishery
The maximization of the present value of the fishery by
employing an optimum dynamic strategy need not but can imply
extinctions of the fishery. Does this mean that economists would
recommend the extinction of fish species under appropriate market
conditions? Social decisions take place in a multiple-objective or
multiple-criterion framework of which economic net benefits are but
one criterion. The responsible economist would generate
information on the present values of the fishery under different
schemes of management. If the highest present value of net
benefits appears to be generated by a pattern of fishing that
eventually would exterminate the fish stock, this would be stated,
along with the information on other schemes that would preserve a
viable fish stock. The decision makers then would understand the
tradeoffs involved and could proceed with their decision.
Source: Charles W. Howe, "The Management of Fisheries," in Natural Resource Economics, John
Wiley & Sons, 1979.
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Dietary Importance of Fish Population
At present, fish comprise 34 percent of the animalprotein for the world's population; in developing
nations, more than 40 percent.
Source: "Assaulting the Seas: Rising Human Tide Overwhelms Oceans," The ZPG Reporter,
July 1991.
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Other Importance of Fish Population
• provides export earnings for poor nations
• important source of jobs and income
• foundation for the culture of
many
regions and towns
• supports a diverse ecosystem
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Alternative Strategies
-
CATCH
Maximum
Sustainable
Catch
-
3
-
2
1
-
TIME
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
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What Happened?
What caused the overshoot and collapse?
Who was responsible?
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Causes of Overshoot
• poor understanding of the level and
the causes of the limit
• science is inadequate, market
prices confuse the issue, those with a
short-term vested interest misrepresent the
situation
• momentum in the system
• long delays in deciding,
responding, affecting
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Causes of Collapse
Collapse happens when the process of
overshooting lowers the limit, and it takes a
long time for the system to recover.
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Examples of Collapse
• drinking too much alcohol
• cutting too many trees
• abusing trust and good will - phone marketing
• relying on debt
• building too many offices or residences
• misleading accounting
• ozone layer, ground water, agricultural soils
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Avoiding Collapse
• understand the limit
• reduce the momentum or look ahead
• speed up response
• avoid the destruction of the system in ways
that lower the limit.
• what is the role of technology?
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Impact of Technology on Ship Effectiveness
-
HIGH TECHNOLOGY
-
CATCH
PER
SHIP-YEAR
LOW
TECHNOLOGY
-
0
0
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FISH
DENSITY
MAXIMUM
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The Fisheries System: Fish
REGENERATION
+-,
(+-, )
+
DENSITY
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
+
FISH
TOTAL
CATCH
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The Fisheries System: Catch
CATCH
FISH
FISH
PRICE
+
DENSITY
+
+
INCOME
+
+
TOTAL
CATCH
+ +
SHIP
OPERATING
COSTS
(-)
DESIRED
GROWTH
(-)
+ CATCH PER
-
PROFIT
(+)
-
+
SHIPS
-
+
INVESTMENT
+
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PURCHASE AND
CONSTRUCTION
COSTS
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The Fisheries System: Investment
(+)
FISH
PRICE
TOTAL
CATCH
+
+
INCOME
+
+
-
PROFIT
OPERATING
COSTS
+
(-)
DESIRED
GROWTH
(+)
+
SHIPS
+,-
+
-
INVESTMENT
+
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
PURCHASE AND
CONSTRUCTION
COSTS
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The Fisheries System Structure
(+)
REGENERATION
+-,
FISH
PRICE
INCOME
+
+
(+)
TOTAL
CATCH
+ +
OPERATING
COSTS
+
SHIPS
+,-
+
-
SHIP
(-)
DESIRED
GROWTH
(-)
+ CATCH PER
-
PROFIT
FISH
DENSITY
+
+
+
(+-, )
+
-
INVESTMENT
+
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
PURCHASE AND
CONSTRUCTION
COSTS
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What can be done?
• Partition the seas
• Establish quotas
• Farm fish
• Move down food chain
• Change consumption preferences
• Reduce destruction and pollution of
fisheries
• Limit ship fleets, technology
• Develop better methods to assess stock
• Change social values and economic
incentives
Fish Banks, Ltd. V 8.02 © 2004 Dennis L. Meadows
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