The Depletion parameter sets the current stock size relative to the historical unfished stock size. This value is used in the model initialization process. Based on the biological and fleet information given, the model selects possible parameter values and runs the historical simulation up to the most recent year.


Estimated current level of stock depletion, which is defined as the current spawning stock biomass divided by the unfished spawning stock biomass. For each simulation a single value is drawn from a uniform distribution specified by the upper and lower bounds provided. This parameter is used during model initialization to select a series of yearly historical recruitment values and fishing mortality rates that, based on the information provided, could have resulted in the specified depletion level in the simulated last historical year. Uniform distribution lower and upper bounds. Positive real numbers (typically < 1)

Custom Parameters

See Custom Stock Parameters for information on specifying simulation-specific values for depletion.

Interactive App

Choose upper and lower bounds for D and the scale in which the depletion should be plotted. Based on these ranges, the MSEtool will display parameter values for 5 simulations in the table. Click on any line of the table to view the distribution of values for that simulation in the figures below.

  • Figure 1 shows the depletion level of an example stock that begins at an unfished stock size and is fished for 50 years. The current stock size is larger in those simulations with a higher depletion size and lower in those simulations with a higher depletion level.