Climate-Induced Changes in Habitat Suitability and Fishing Grounds for a Forage Fish and Three Demersal Species in the Inner Sea of Northern Chilean Patagonia

Abstract

Climate change is altering environmental conditions in the Patagonia ecosystems, with potential consequences for the distribution of marine species that sustain artisanal fisheries within the inner sea of northern Chilean Patagonia (41°28.6′S–45°30′S). We evaluated current and future habitat suitability for one forage species (Falkland sprat, Sprattus fuegensis) and three demersal predators (Macruronus magellanicus, Merluccius australis, and Genypterus blacodes) using a species distribution modeling approach (Maxent). Occurrence data derived from fisheries records and acoustic surveys were combined with environmental predictors from Bio-Oracle under three climate scenarios (SSP1–2.6, SSP2–4.5, SSP5–8.5) for the period 2020–2050. Results indicate that the habitat suitability of demersal species is primarily associated with dissolved oxygen and bottom environmental conditions, whereas Falkland sprat is mainly driven by surface temperature, salinity, and phytoplankton concentration. Current suitable habitats are concentrated in the Gulf of Ancud and adjacent fjord systems, while demersal species occupy broader areas, including inner and outer margins. Future projections suggest spatial redistribution rather than uniform loss for demersal species, while the Falkland sprat shows displacement toward thermally stable and sheltered areas. The magnitude of projected shifts ranges from 10 to 20 km, depending on the species and scenario. These changes may alter the spatial overlap between predators and prey and affect the accessibility of fishing grounds for artisanal fleets. Although projected shifts are moderate, they are comparable to the operational scale of artisanal fisheries and may therefore have significant socioeconomic implications. This study highlights the need to incorporate climate-driven habitat changes into fisheries management and spatial planning in highly dynamic fjord ecosystems.