Underwater umbrellas protect Florida corals from bleaching

Researchers in the Florida Keys have successfully used small underwater umbrellas to mitigate coral bleaching during extreme heat. A study published in Frontiers in Marine Science reveals that approximately 20 small shades, positioned about 30 centimeters above specific coral colonies, helped reduce light exposure.

While the devices do not lower water temperatures, they block the intense light that exacerbates bleaching when combined with high heat. During the summer of 2024, protected colonies of two Caribbean brain coral species, Pseudodiploria clivosa and Colpophyllia natans, lost less color and in some instances began to recover.

The experiment was conducted at Newfound Harbor following a devastating 2023 season where exceptional marine temperatures caused widespread bleaching and high mortality rates. Led by Karen L. Neely of the National Coral Reef Institute at Nova Southeastern University, in collaboration with the University of Miami, the study notes that while protecting individual colonies is feasible, scaling this method to entire reef systems remains a significant challenge.