NOVA and PBS Digital Studios have produced a series of videos called “Gross Science.” One video explains how many beaches in the Caribbean, Hawaii, the Maldives and many other places around the world ...

The Netflix documentary Chasing Coral makes passing reference to an extraordinary claim: Beaches are made of parrotfish poop. Here’s the thinking: These colorful beaked creatures of the reefs eat ...

You'll probably hear the parrotfish before you see them. The animals chomp through solid rock and coral with fused beaks. When you're snorkeling on one of Hawaii's reefs, the noise is unmistakable.