Assessment of the Anchovy Stock Using a Beverton–Holt-Driven Production Model in China Waters of the Bohai and Yellow Seas

Abstract

The classical surplus production model is less explanatory when biomass is low and the catch is high, and also does not explicitly include a stock recruitment process. Nevertheless, a classical Schaefer surplus production function (SF) has been predominantly used for current anchovy (Engraulis japonicus) stock assessments in the Bohai and Yellow Seas in China. The Beverton–Holt-driven production function (BHDPF) model may mitigate drawbacks of the classical SF model. To assess status of the anchovy stock in the Bohai and Yellow Seas, the SF, BHDPF, and Stock Synthesis 3 (SS3) (an integrated analysis model) were used. The SF suggested a recovered stock, with stable catch, whereas the BHDPF and SS3 models suggested that the stock biomass was the lowest during the study period, thereby necessitating a reduction in catch. BHDPF and SS3 were consistent with one another the SF. Under the BHDPF assumption, increasing and decreasing biomass trends may result in countertrend catches, and high catches at low biomass. The BHDPF may serve as an assessment alternative for fisheries lacking age-structure data. Abundance index data plays a significant role in the current assessment of the Bohai and Yellow Seas anchovy stock, and more research is needed to improve its accuracy.