Deepest ever discovered coral bleaching: study

This study reveals coral bleaching down to 90m depth at an Indian Ocean atoll, the deepest bleaching recorded, occurring without shallow reef bleaching. Sustained "thermocline deepening" linked to an extreme Indian Ocean "Dipole" exposed mesophotic, deeper, corals to warm surface waters. Additionally, internal waves further modulated temperatures locally, through downward heat fluxes. This demonstrates mesophotic reefs' potential thermal vulnerability, hidden from sea surface temperature bleaching metrics. Their uniqueness underscores the need to understand oceanography in predicting susceptibility. As researchers increasingly monitor mesophotic reefs, recording bleaching will likely rise, pressing us to protect these biodiverse, threatened ecosystems. (Nature)