Modeling time-varying growth WHAM

Workshop on assessment methods for stocks with little or no age data

Ocean Frontier Institute (Dalhousie University).

Here you can find the slides and examples that my colleague (Jane Sullivan, NOAA) and I made for the workshop Assessment methods for stocks with little or no age data organized by the Ocean Frontier Institute (Dalhousie University).

In our presentations, we provide a quick overview of the modeling of length information and time-varying growth in the WHAM model, how to implement a model from scratch, and several examples. All required files for the examples can be downloaded on this site.


We prepared three simple examples to show how to implement your model in WHAM.

  • Case 1: Only uses age compositions. Growth modeled using empirical weight-at-age or nonparametric WAA.
  • Case 2: Uses marginal length compositions. Growth modeled using parametric LAA.
  • Case 3: Uses marginal length compositions and conditional length-at-age data. Growth modeled using parametric LAA.

You can also find these cases here and more examples applied to fish stocks in Alaska here.

Giancarlo M. Correa, Ph.D.
Giancarlo M. Correa, Ph.D.

Fisheries scientist.