Californian anchovy, Engraulis mordax is a small pelagic schooling fish distributed between Southern Baja California, Mexico, and Northern British Columbia, Canada (Schwartzkopf et al. 2022). This is an important forage species for many predators, including fish, birds, and mammals. Californian anchovies are divided into three stocks: northern, central, and southern. The southern stock extends from central-southern Baja California to the Gulf of California, Mexico (Kuriyama et al. 2022)(Schwartzkopf et al. 2022). 

Stock divisions are based on electrophoretic, morphometric, and meristic characteristics (Vrooman et al. 1981) and growth rates (Parrish et al. 1985). These characteristics demonstrate regional and spatial differences between stocks but do not appear to have a genetic structure (Lecomte et al. 2004).

(Lecomte et al. 2004) proposed a basin model for the whole distribution of this species, in which, under adverse conditions, the distributions contract to an optimum area while the population crashes and from which it would expand when conditions were restored. In addition, the stocks show annual and seasonal movements and distributions that overlap and interchange with each other (Schwartzkopf et al. 2022).

In the area of distribution of the southern stock, the harbor with significant anchovy landings is Sonora (DOF 2022)​. In the Gulf of California, the anchovy is part of a multispecific fishery that mainly targets the Pacific Sardine (also known as South American pilchard, Sardinops sagax) (García-Sandoval and Chávez 2019)(DOF 2022). Assessments of Californian anchovy do not include Baja California and focus on the Gulf of California, where the main fishery for small pelagic fish occurs, and coincides with Region B proposed by INAPESCA to manage the fishery (DOF 2019).