The R package decamod was developed for doing stock assessments of New Zealand rock lobster stocks. The operating model (OM) is a length structured model coded using the R Template Model Builder (RTMB) software. MLE inference can be done using the R package nlminb and Bayesian inference can be done using a range of different R packages.
The decamod package can be installed using:
remotes::install_github(repo = "quantifish/decamod")