Population aging occurs at the start of each year. The model is seeded with initial cohort sizes for all stocks. The maximum age for all stocks is fixed at five years. Brood year survival rates during simulation years can be deterministic or stochastic. Maturation rates are stock and age specific for all stocks.
Some stocks have variable maturation rates.
Production functions for both hatchery and natural stocks are estimated from historical data. This type of analysis involves the reconstruction of an annual series of abundance estimates using catch and escapement data and making assumptions about natural and incidental mortalities. Model parameters can be obtained from the PSC Chinook Technical Committee, or advanced users can utilize there own parameters. Harvest allows the operator to change parameters and view results interactively. Parameter values can be changed by using the mouse or keyboard.