The Pelagic Seascape of the Gulf of California

Abstract Context. Pelagic seascapes describe the ocean as a changing mosaic of habitats defined by multiple environmental properties. Their ecological relevance remains insufficiently evaluated in dynamic regional systems. Objectives. We evaluated whether the globally derived Pelagic Seascape Habitat Classification captures seasonal and interannual variability in the Gulf of California (GC) and assessed its correspondence with environmental conditions and biological responses. Methods. Monthly habitat coverage and habitat diversity (Shannon index) were analysed for 2003–2024 alongside net primary productivity and sea level anomalies. Seasonal and El Niño–Southern Oscillation (ENSO) configurations were compared with documented biological changes and pelagic fisheries landings reported in the region. Results. The pelagic habitat C21 reached a maximum coverage of 94.3%, showing the greatest expansion potential among the habitat categories. Winter and negative ENSO conditions were associated with greater C21 coverage, higher productivity, lower sea level, and lower habitat diversity. Summer and positive ENSO conditions coincided with C21 contraction and expansion of C15, C3, and C13, together with lower productivity and greater habitat heterogeneity. Interannual changes in the pelagic seascape corresponded well with documented responses of jumbo squid, euphausiids and reported pelagic fisheries catches. Conclusions. Pelagic seascapes capture coherent environmental and ecological variability in the Gulf of California, supporting their use as regional indicators of ecosystem state and as a framework for tracking climate-related ecosystem change. Their broader application to ecosystem monitoring and fisheries management requires regional validation and would benefit from reduced product latency.