Albino-Martínez, O. and Rosales-Casián, J.A., 2024. Ecology of economically important fish at a temperate Pacific Island of Baja California, Mexico. Journal of Coastal Research, 40(5), 919–928. Charlotte (North Carolina), ISSN 0749-0208.

Economically important fish were caught in rocky reefs around Isla San Martin, Baja California, Mexico to determine the composition and spatio-temporal variations, their possible relationship with temperature, upwelling and depth, and the size structure of the most abundant species. Five seasonal surveys were carried out using traps and hook-and-line at four different sites from June 2021 to May 2022. A total of 595 fish individuals (417 kg) were caught, comprising of 23 species from 10 families, and the Sebastidae family contributed the largest number of 12 species. The most abundant fish species were Caulolatilus princeps, Paralabrax clathratus, Semicossyphus pulcher, Paralabrax nebulifer, Sebastes auriculatus, S. umbrosus, and S. rastrelliger that contributed 90.2% of the total abundance. C. princeps contributed 60.8% of the abundance and 60.2% of the biomass. The first three fish species were the most important in terms of relative abundance and frequency of occurrence. The catch means (abundance and biomass) per trap or angler did not change over time; however, between sites, the average fish catch per trap (abundance and biomass) was significantly different, which presented a positive and significant relationship with depth, only. The fish richness (number of species) varied between nine (fall 2021) and 14 species in spring 2021 and 2022. The highest diversity of fish species (H' = 1.9) occurred in summer (C. princeps 41.1% abundance), and the lowest diversity (H' = 1.0) during fall (C. princeps 74.1%. abundance). Among fishing sites, the greatest diversity occurred close to Isla San Martín (El Bufeo, H' = 2.1), and the lowest diversity in the deeper sites far from the island (Bajo 6, H' = 1.0). Caulolatilus princeps presented 100% frequency of occurrence, while Chromis punctipinnis, Halichoeres semicinctus, Medialuna californiensis, and Sebastes serranoides occurred with the lowest value (4.5% each).