Further testing of the model for the revised South African sardine stock structure hypothesis

Further testing of the model for the revised stock structure hypothesis for South African sardine is carried out incorporating some new modifications to the model. Conflicts between data – particularly in the model’s ability to fit the hydroacoustic survey estimates of November biomass off the South Coast in recent years – are investigated through alternative weighting of length frequency data and variability about the growth curves. It is shown that the data are unable to reliably inform the passive movement of Warm Temperate Sardine from the South to the West Coast, and an informative prior distribution is required, but that the level of passive movement has little influence on the overall recruitment to the West Coast. Results are also shown assuming the same survey selectivity for both coasts and if the model is additionally fitted to parasite prevalence‐at‐length data.