Potential spatial mismatches between marine predators and their prey in the Southern Hemisphere in response to climate change

Abstract

Global change is rapidly reshaping species' habitat suitability ranges, hence leading to significant shifts in the distribution ofmarine life. Contrasting distributional responses among species can alter the spatial overlap between predators and prey, potentiallydisrupting trophic interactions and affecting food web dynamics. Here, we evaluate long-termchanges in the spatial overlap of habitat suitability ranges for trophically related species, including crustaceans, fish, penguins, and pinnipeds across12 Large Marine Ecosystems from the Southern Hemisphere, merged into three primary regions: South America, SouthernAfrica, Australia and New Zealand. To this aim, we first use Boosted Regression Trees (BRTs) to hindcast and project species-specificchanges in suitable habitat from 1850 to 2100 under two future climate scenarios: SSP1-2.6 (low climate forcing) andSSP5-8.5 (high climate forcing). We then analyze changes in species habitat suitability and potential predator–prey spatial overlaps.Findings reveal that marine species generally exhibit changes in their suitable habitats, with pronounced shifts towardshigher latitudes under the SSP5-8.5 scenario. However, contrasting trends emerge among predators across functional groupsand regions of South America, Southern Africa, Australia and New Zealand. These variations highlight the need for species andregional-specific management responses. We also project contrasting spatial mismatches between predators and prey: predatorsexperiencing declines in suitable habitat tend to exhibit greater overlap with their prey in future scenarios, whereas those withexpanding suitable habitat show reduced spatial overlap with their prey. This study provides valuable insights that can informspatial management strategies in response to climate change and illustrate how climate change may weaken species' ability toadapt to climate-driven environmental changes due to trophic disruptions.