Oh, that’s right. Your precious Hawaiian beach vacation was actually a frolic through epic amounts of doody. Specifically, the doody from a very special kind of critter: the parrotfish. You see, parrotfish are quite partial to the algae that grow on coral, and they gnaw it off with two impressive rows of fused, beak-like teeth (hence their name). Simply by chewing on reefs, a large Hawaiian parrotfish can ingest a coral’s calcium carbonate and poop out up to 800 pounds of sand each year, according to marine biologist Ling Ong of Hawaii’s SWCA Environmental Consultants. One Australian species, she notes, produces up to one ton per year.