Updated “Replacement Yield” model fit to catch and survey data for the South coast and for the West coast Kingklip resource of South Africa

A Bayesian “Replacement Yield” model is applied to the total annual catches and the survey abundance estimates for the South African kingklip resource off the South coast over the 1986 to 2021 period and that off the West coast over the 1986 to 2020 period. A posterior median replacement yield (RY) of 1 430 tonnes is estimated for the South coast and of 2 871 tonnes for the West coast; these values are suggested as upper bounds for the catch limit recommendations. Setting the catch limit at the 25th percentile of the posterior distribution results in values of 1 316 t and 2 731 t for the South and West coasts respectively (in 2019, the corresponding values were 919 t and 2 986 t). The corresponding posterior median rates of increase over the last five years are estimated at about 1.7% and 2.9% for the South and West coasts respectively.