The Casal2 software implements an updated generalised age-structured marine population model that allows more flexibility in specifying the population dynamics, parameter estimation, and model outputs than CASAL. Models are built with user-defined categories such as area, sex and maturity. These structural elements are generic and not predefined (as they are in CASAL), but are easily constructed. Casal2 models can be used for a single population with a single anthropogenic event (i.e., a single fishery), or for multiple species and populations, areas, and/or anthropogenic or exploitation methods.
Casal2 is open-source and is available at https://github.com/NIWAFisheriesModelling/Casal2
Initial comparisons of CASAL and Casal2 show that these programs provide the same stochastic results, and identical empirical results for estimation of key productivity parameters. We invite Members to test Casal2 on their stock assessments and / or on simulation data. Any issues should be registered through the github website. We also suggest that one or multiple assessments of toothfish be included in the Casal2 unit-testing.