Spatial Population Model (SPM)

SPM is an advanced software package developed by NIWA to help with fish stock assessments. The software is written in C++ and is available under an open source licence. SPM was designed to allow populations with a complex spatially structure to be easily modelled. It implements an age-structured population model with unlimited user-defined categories (for example, sex, maturity, species, or area). It can be used for a single stock for a single fishery, or for multiple stocks, areas, and/or fishing methods. The user can choose the sequence of events in a model year. The observational data that can be used include catch-at-age or catch-at-size data from commercial fishing, survey and other biomass indices, survey catch-at-age or catch-at-size data, and tag-release and tag-recapture data.

SPM can be used to generate point estimates of the parameters of interest, calculate profiles, and generate Bayesian posterior distributions using Monte Carlo Markov Chain methods. SPM can also be used to simulate observations from a given model for use in management procedure evaluations or other simulation experiments. To download the user manual for SPM click the following link ftp://ftp.niwa.co.nz/software/casal/SPM.pdf. For a download of the installer for windows click the following link ftp://ftp.niwa.co.nz/software/casal/Setup_SPM.exe. For any assistance or queries please contact the development team at casal2@niwa.co.nz.