Variation in population dynamics and abundance of the bigeye croaker Micropogonias megalops in the Northern Gulf of California

Abstract

The bigeye croaker Micropogonias megalops is an endemic Sciaenidae fish species of the Gulf of California. Although it is a stock that has been exploited for nearly three decades, its biological and fishery information has been limited over time. Therefore, its recent and current population status is poorly known. This study analyzed biological and fishery data for M. megalops in the Northern Gulf of California for the period 1995–2020. Variation of species population dynamics has been analyzed for years with biological information (2000, 2010, and 2020), finding points in time with relative decreases and increases in growth and natural mortality values. An interannual abundance analysis was performed, obtaining biological reference points for the resource through two surplus production models, the Monte Carlo (CMSY+) and the Bayesian state–space Schaefer surplus production model (BSM) methods. The results for management (based on the BSM analysis) indicated that the currently relative stock biomass level is at 79% of virgin biomass (k), which means a recovery compared to the 2017 biomass level (64% k) that has been the lowest in this fishery history. According to the Kobe phase plot, the resource has been harvested in a healthy way, showing a maximum sustainable yield of 8 248.52 t and current status of sub-exploited.