Data from: Oxygen supersaturation could protect reef-building corals against acute thermal stress

Ongoing climate change is constraining the availability of molecular
oxygen (O2) on coral reefs. The field has recently invested considerable
resources to quantify the effects of hypoxia on corals. However, drivers
of reef oxygen decline will not only expose corals to more frequent
episodes of hypoxia but also limit peak daytime oxygen levels. Here, we
test the theory of oxygen-mediated thermal performance on three
reef-building corals by comparing their thermal thresholds under three
bulk seawater oxygen concentrations in low flow conditions: 10 mg O2 L⁻¹,
6.5 mg O2 L⁻¹, and < 2 mg O2 L⁻¹. We hypothesized that when the
photosynthetic machinery of their microalgal symbionts was impaired,
corals in higher oxygen treatments would use oxygen from the bulk water to
supplement their heightened metabolic demands under heat stress, thereby
increasing their thermal thresholds. These datasets include mortality,
photochemical efficiency, and metabolic rates for three coral species from
the Red Sea in an acute thermal stress assay under varying oxygen regimes.