Welcome to Greater Tuna, a simulation game exploring sustainable management of renewable resources. The
game appears at the bottom of the page (as long as your Web browser supports Java).
Object of the game:
Find the profit-maximizing level of fishing effort for a sustainable harvest of a search fishery.
How to play:
Each turn you must decide how much effort to devote to fishing. Enter the value using the Effort slider.
When you're happy with your level of effort (!), click the "Next Turn" button to see how things turn out.
Details about the fish:
This particular fishery is described by a biological growth function of the following form:
- Spawn = NatGrow*StartPop*(CarryCap-StartPop)/CarryCap
where Spawn is the number of new fish, StartPop is the population at the beginning of the period, and NatGrow
and CarryCap are parameters. The population at the end of the period will be given by:
- EndPop = StartPop + Spawn - Harvest
where Harvest is the number of fish harvested by people (more on that below). This will become the starting
population for the next period. (Just to make sure there aren't any ambiguities please note that Spawn, Harvest, EndPop and
StartPop may vary with time while NatGrow and CarryCap are parameters.) It will be up to you to determine the numerical values
of NatGrow and CarryCap. This should be a matter of observing a few data points and doing a little algebra.
Details about the industry:
The harvest of fish is given by a function of the form:
- Harvest = Tech*StartPop*(Effort/100)
where Harvest is the number of fish caught, Tech is a parameter (initially unknown), and Effort is the level
of effort. (The factor of 100 appears here for computer convenience rather than economics: it allows the slider to read from
0 to 100 instead of from 0 to 1.) Finally, the fishery is also a price-taker in both the fish and labor markets. Its total
revenue and total cost are given by:
- Revenue = $1*Harvest
- Cost = $2000*(Effort/100)
The goal of the game is to find the profit-maximizing level of effort AND to end up with a sustainable population--that
is, one for which StartPop equals EndPop at the optimum level of effort.
Click on the link below to start the game: