Impact of climate change and ENSO on marine aerobic habitat in the South East Pacifc

On-going climate change is now recognized to yield physiological stresses on marine species, with potentially detrimental effects on ecosystems. Here, we  se metbaolic constraints to assess potential changes in suitable aerobic habitat in the South East Pacific. Our approach uses physiological traits (critical  xygen thresholds and metabolic indices) and climate velocities indicating the level of exposure to environmental changes simulated (CESM-LE) under a  RCP 8.5 scenario. The SEP is chosen as a case study as it hosts an Oxygen Minimum Zone and seamounts systems sustaining local communities through  artisanal fisheries relying on a number of endemic species. Our results reveal that changes in aerobic habitat are constrained by the oxygen distribution and by contrasting oxygen trends (including a re-oxygenation in the upper OMZ) and warming trends. Hence, while climate change highly impacts seamount systems, the OMZ ans its vicinity can be considered a “safe” area as it also experience the slowest changes. Contrasted latitudinal and vertical changes would likely result in altered trophic interactions. As the SEP also experiences the consequences of the El Nino Southern Oscillation (ENSO), we compare the impacts of climate change to ENSO events at the 2100 horizon.