https://phys.org/news/2018-06-coral-reefs.html

Without coral to help absorb the shock, a once-in-a-century cyclone would wreak twice the havoc, with the damage measured in the tens of billions of dollars, the team calculated.

"Coral reefs serve as natural, submerged breakwaters that reduce flooding by breaking waves and reducing wave energy," said Michael Beck, lead scientist at The Nature Conservancy research and environmental group, and a professor at the University of California in Santa Cruz.