The western coast of Baja California Sur lies within a transitional oceanographic zone influenced by distinct water masses and the California Current, creating a highly productive ecosystem that supports a population of Merluccius productus (Dwarf hake), a species of ecological and potential economic importance. Despite its relevance, information on its distribution and abundance remains limited. This study analyzed data from eight fishery-oceanographic surveys that combined midwater trawl sampling with conductivity, temperature, and depth measurements to evaluate biological and environmental variables. The objectives were to characterize the size structure and spatial distribution of Dwarf hake and to identify the oceanographic variables influencing its presence and catch per unit of effort. A delta generalized additive mixed modeling approach was used to analyze both presence or absence and catch per unit of effort based on environmental and geographic predictors. This framework included a binomial model for occurrence and a gamma model for catch rates conditional on presence. Model selection and validation were conducted using the Akaike Information Criterion. The binomial model explained 27.3 percent of the deviance, whereas the gamma model explained 79.8 percent. Temperature, distance to the edge of the continental shelf, longitude, and survey (temporal factor) were significant predictors of species presence. Once present, fishing haul depth, salinity, and distance to the continental shelf edge influenced catch rates. Individuals of Dwarf hake ranged from 3.5 to 40 (sd = 6.6) centimeters in total length and were captured between 19.5- and 321.5-meters depth, with shallower distributions observed at night. Highest abundance occurred during summer in the Gulf of Ulloa. This study provides the first comprehensive assessment along the Baja California Peninsula and identifies previously unreported areas of high density.
Pacific hake, Environmental variables, CPUE, New fishery, Oceanography, Temperature
