Chapter 14. The Tucannon Salmon
System dynamics may be used to help policy makers and environmental
managers improve their instinctive understanding of dynamic behavior. This
chapter illustrates how this may be done with a simulation model of the
salmon population of the Tucannon River (see Figure 14.1) The model simulates
the long term trends in the population over successive generations. The
model is then used to simulate the impact of land use development, hydroelectric
development and harvesting. The Tucannon model illustrates the value of
building more than one model of the same system. As a long term model of
the entire population, it serves as a natural accompaniment to the short
term model from the previous chapter.

Figure 14.1. Location of the Tucannon River.
This chapter demonstrates how simulation might be used in fishery management. Fisheries have declined in the northwest and around the world. You will learn how previous simulation models have been used to help managers deal with the many factors contributing to the decline. This chapter concludes with exercises to apply and improve the Tucannon model. It also includes an interactive exercise to place you in the role of fishery manager.