Nicolás Muñoz‐Aroca

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.

Predicting changes in the spatial distribution of marine resources under climate change (CC) is key for sustainability, since some species may change their historical fishing zones and/or the spatial boundaries set for managing fisheries. Chile is a leading country in fishing landings and products (e.g., fish oil and fishmeal). This productivity is influenced by the Humboldt Current, one of the most important upwelling systems. Although 70% of pelagic and demersal landings are caught in central‐southern Chile (32° S–42° S), little is known about the impacts of CC on this ecosystem. Thus, we modelled the habitat suitability (HSM) for the main stocks in the area: anchovy, common sardine, Chilean hake, yellow prawn, carrot prawn and nylon shrimp. We projected the HSM for each species considering ocean abiotic conditions from 2040 to 2050 using Social Shared Pathways scenarios (SSP1, SSP2 and SSP5) from Bio‐Oracle. HSM exhibited high performance in predicting the current spatial variability for the six species. The CC projections indicated significant changes in the spatial distribution of all species (i.e., reduction in size, poleward shift, and deepening of core habitat), especially in common sardine, anchovy and carrot prawn. In the long term, these changes may affect the latitudinal boundaries set for managing fisheries, the design of stock assessment and catch monitoring programs, and fishing effort/costs in each fleet. These findings will help decision‐makers, researchers and users to visualise the potential impacts of future environmental variability on the southern Humboldt ecosystem and to design plans and actions to adapt the management of Chilean fisheries to CC.