“Replacement Yield” model fit to catch and survey data for the South coast and for the West coast kingklip resources off South Africa to include data up to 2023

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 and off the West coast over the 1986 to 2023 period. A posterior median replacement yield (RY) of 1 188 tonnes is estimated for the South coast and of 2 694 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 1 032 t and 2 559 t for the South and West coasts respectively (in 2021, the corresponding values were 1 316 t and 2 731 t). The corresponding posterior median rate of decrease over the last five years is estimated at about 0.9% for the South coast and, with an increase of about 1.3% for the West coast.