�y��vlog

They found that the disease not only reduces susceptible coral populations but also diminishes crustose coralline algae, the resilient pink crust that is crucial for building reef structure.

Some scientists mistake them for coralline algae, which also form crusts on reefs but help promote growth of the living structures.

Whereas coralline algae form thin, hard crusts that are pink or whitish, peyssonnelid algae make thicker, brown or dark red crusts that are often a little squishy above a hard base.

They include small size, which may reduce physiological requirements, and their ability to feed on a variety of food sources, despite preferring a diet of coralline algae.

"My colleagues and I have been studying modern and fossil coralline red algae and related carbonate deposits for 15 years," says Yasufumi Iryu, a professor at Tohoku University's Department of Earth Sciences within the Graduate School of Science.