New Insights Into the Spatial Zones of High Scomberomorus sierra Habitat Suitability in the Eastern Pacific Ocean Based on Ecological Niche Modeling

ABSTRACT

Understanding the environmental niche and potential distribution of the Pacific sierra ( Scomberomorus sierra ) is critical for fisheries management across the eastern Pacific Ocean (EPO). We used MaxEnt to model S. sierra habitat suitability across the EPO (30° N–30° S to 120° W) using 169 vetted occurrence records and monthly CMEMS environmental layers (2004–2018): sea surface temperature (Temp), sea surface salinity (Sal), surface geostrophic currents (UCOMP, VCOMP), mixed layer depth (MLD), and sea surface anomalies (SSA). Models were tuned with ENMeval (20 feature/regularization combinations) and evaluated with AUC and AICc. The best model (linear–quadratic features, RM = 1) had AUC = 0.846. Variable importance (percent contribution and permutation importance) identified SSA, Temp, and MLD as primary drivers of habitat suitability. Predicted high‐suitability areas occur off northern Mexico including the Gulf of California, in the Gulfs of Tehuantepec and Panama (as a continuous band below ~10° N), and as a coastal/insular band off Ecuador–Peru extending toward the Galapagos. Clustering of pixels with probabilities of occurrence > 0.67 revealed four environmentally distinct high‐suitability zones: northern (Mexico–Gulf of California; deeper MLD), Tehuantepec (distinct surface‐current regime), central (Colombia–Central America; warmer, lower salinity), and southern (Ecuador–northern Peru and Galápagos; cooler, higher salinity). These findings suggest environmental heterogeneity may underlie regional variations in habitat use and have implications for regionally tailored management and monitoring. Future work should integrate life‐stage data, finer resolution oceanographic drivers, and genetic or movement data to test population connectivity and improve management‐relevant projections.