Building the Fish Banks Model and Renewable Resource Depletion

6
2 PLAYING THE FISHING GAME
D-4543-2
The numerical values used in The Fishing Game as well as in the model you will
build are not realistic. The values were chosen to maintain consistency with the original
Fish Banks, Ltd. game developed by Dennis Meadows as well as with Renewable
Resource Depletion (D-4263) which is the second half of this document. Nevertheless, the
numbers used are altogether consistent and do not affect the qualitative behavior of the
model. It may be helpful to consider the numbers as representing their values in
thousands.
2.1 Role Description
You will be fishing in an area that has an optimal fish population of 1200. A
natural restriction occurs once the fish population reaches 1200, so that overcrowding
doesn't occur. The restriction is a reduced reproduction rate so that the population
remains at 1200 while the natural habitat of the fish stays unchanged.
The presence of a fishing industry in the area disturbs the natural habitat of the
fish. When the fishing industry takes only small amounts of fish from the population, the
fish are able to quickly regenerate and regain their optimal population of 1200 fish. If the
small depletions by the fishing industry continue steadily over time, the fish will never
reach 1200, but will establish a new optimal population at less than 1200. However, if the
fish population drops dramatically, the number of fish laying eggs is so small that the
population takes a very long time to recover even when undisturbed by the fishing industry
during the regeneration period.