Climate warming is expected to intensify hypoxia in the California Current System (CCS),
threatening its diverse and productive marine ecosystem. We analyzed past regional
variability and future changes in the Metabolic Index (Φ), a species-specific measure of the
environment's capacity to meet temperature-dependent organismal oxygen demand. Across
the traits of diverse animals, Φ exhibits strong seasonal to interdecadal variations
throughout the CCS, implying that resident species already experience large fluctuations in …