Book excerpt: Takes children to the underwater world of Australia's Great Barrier Reef for a prime example of how a complex ecosystem depends on its keystone species. Sharon Wismer—reef ecologist and mom—is the best tour guide a kid could have for a visit to the underwater world of Australia’s Great Barrier Reef. Alice Wong’s richly detailed, accurate watercolors take a boy and girl snorkeling to see the fishes that maintain the ecological balance between the corals and their main competitor, algae. Without the fish species that brush, crop, scrape, excavate, and browse the algae, coral reefs would die. A coral reef is a brilliant and colorful example of how a complex ecosystem functions and why its keystone species are critical to its health. The Great Barrier Reef is one of Earth’s most celebrated natural treasures. Here children discover why the reef is threatened and what we can all do to help protect it. Endorsements are coming from Charlie Veron (“the godfather of coral,” featured in the 2017 film Chasing Coral) and David Bellwood, a world-renowned reef fish ecologist whose lab is the source of much of the information in this book. Keepers of Reef is the rare children’s book combining cutting-edge science with narrative and pictorial magic. Thorough backmatter sources and resources are included.