Evaluating future climate change exposure of marine habitat in the South East Pacific based on metabolic constraints

Abstract

IntroductionOn-going climate change is now recognized to yield physiological stresses on marine species, with potentially detrimental effects on ecosystems. Here, we evaluate the prospect of using climate velocities (CV) of the metabolic index (Φ) for assessing changes in habitat in the South East Pacific.MethodsOur approach is based on a species with mean ecophysiotype (i.e. model species) and the use of a global Earth System Model simulation (CESM-LE) under 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.Results and DiscussionOur results indicate that CVΦ pattern is mainly constrained by the oxygen distribution and that its sign is affected by contrasting oxygen trends (including a re-oxygenation in the upper OMZ) and warming. We further show that CVΦ is weakly dependent on physiological traits composing Φ, which conveys to this metrics some value for inferring the projected mean displacement and potential changes in viability of metabolic habitat in a region where physiological data are scarce. Based on sensitivity experiments to physiological traits and natural variability, we propose a general method for inferring broad areas of climate change exposure regardless of species-specific Φ. We show in particular that for the model used here, the upper OMZ region can be considered a “safe” area for the species with ecophysiotype close to that of 71 species used to derive the model species. Limitations of the approach and perspectives of this work are also discussed.

Simulated Abrupt Shifts in Aerobic Habitats of Marine Species in the Past, Present, and Future

“…Despite the obvious advantages, it can be challenging to get more generalized results with this approach due to the variety of taxa living in the ocean. Previous studies using the metabolic index therefore have assessed habitability in the ocean by calculating the metabolic index for all species provided by Deutsch et al (2020) and then constructing a mean habitat (Santana-Falcón et al, 2023) or calculate mean metabolic traits first to calculate the metabolic index for a mean ecophysiotype (e.g., Parouffe et al, 2023;, or describe only individual species (e.g., Howard et al, 2020;Parouffe et al, 2023). Compared to these very valid approaches, here, the construction of the nine ecophysiotypes allows to generalize the patterns of habitability and changes therein, while still keeping a species-specific complexity with regards to hypoxia vulnerability V h , its temperature sensitivity E 0 , and critical oxygen demand.…”

“…For example, the rapid spreading of temperature‐dependent deoxygenation has led to a widespread loss of aerobic habitat and thereby contributed to the marine mass extinction of marine species at the end of the Permian Period (Penn et al., 2018). Likewise, in response to climate change, ongoing warming and deoxygenation will not only affect the future distribution of marine species, but could lead to extirpation of species with small tolerance toward deoxygenation (Howard et al., 2020; Parouffe et al., 2023; Penn & Deutsch, 2022). Depending on the future emission pathway, the projected habitat loss may even be irreversible for centuries (Santana‐Falcón et al., 2023).…”