Florida Keys scientists shaded corals with shade-cloth umbrellas that cut light by 60%

In an October 2026 Fast Company report, researchers describe testing underwater 'umbrellas' made of shade cloth, the textile used to protect plants on farms and in gardens, above individual corals in the Florida Keys. Lead author Karen Neely of Nova Southeastern University says the cloths reduced light by 60%, and that the study was published in Frontiers in Marine Science.

Heat stress during the summer of the study was the second highest on record. Corals under shade lost less color than expected, and in some cases recovered some color. The color loss reflects the death of the algae that live with corals.

Neely says shade does not cool the water, but heat works synergistically with light, so cutting light cuts stress and bleaching.

Heat is the primary driver of bleaching, but light multiplies it.

Cheap farm shade cloth is readily available.

It gives reefs relief while climate change itself is addressed.

When the primary driver cannot be fixed quickly, remove a secondary one that works with it.

The article reports the corals under shade bleached less than expected, but the excerpt does not say how the shading could be scaled up. It stresses that addressing climate change is still needed to protect corals.