A recent study published in Nature Communications has found that mesophotic reefs, which are deeper-water coral ecosystems, are more vulnerable to bleaching than previously believed. The study, conducted in the Indian Ocean's Chagos Archipelago, observed the deepest instance of bleaching ever recorded in the "twilight zone" of the ocean. The researchers discovered that the bleaching corresponded with the timing of the Indian Ocean Dipole, a climate pattern similar to El Niño, which deepened the warm waters in the area. This observation is significant because it suggests that mesophotic reefs in other regions could also be at risk of bleaching. However, the corals in the study had largely recovered their color by 2022. The researchers hope that future studies will shed light on the physical processes behind thermocline deepening and its duration. [Extracted from the article]