(Note: This interview first aired back in April.) On today's ST, an update on the fight to save coral reefs, and why this fight is so crucial for our entire planet. Our guest is science writer Juli Berwald, who received her PhD in ocean science from the University of Southern California. She's also a science textbook writer and editor, and her writing has appeared in The New York Times, Nature, National Geographic, and Slate. She tells us about her new book, "Life on the Rocks: Building a Future for Coral Reefs." It's a work that is, per The New York Review of Books, "splendid.... Berwald's great strength lies in revealing a fast-moving, complex global catastrophe through easily understood case studies."