Mary Cerullo decided at thirteen that she ought to become an oceanographer. Although her career has always centered around the ocean, she discovered that she preferred exploring many different topics, which led her to teach and write about the ocean instead. She likes to immerse herself in her topic, so a few years ago Mary went on an underwater dive with ten Caribbean reef sharks. She has written 20 nonfiction books on ocean life for children, including City Fish, Country Fish, Sharks (a School Library Journal Best Book of the Year), Octopus (a Junior Library Guild Selection), Giant Squid (an Outstanding Science Trade Book selection by the NSTA and the CBC), and The Truth About White Sharks (IRA Teacher's Choice Award). Mary is the associate director of Friends of Casco Bay, an environmental group on the Gulf of Maine. Bill Curtsinger, like many explorers before him, first traveled to Antarctica as a young sailor. He was in the Navy Combat Camera Group, assigned to photograph the work of National Science Foundation researchers. In the years since, Bill's photography has appeared in numerous books and magazines, including National Geographic, Life, Time, Newsweek, Outside, Natural History, and Smithsonian.