Children's LiteratureDolphins, like humans, are mammals, but they live in the ocean, communicate with clicking sounds, and use echolocation to find their next meal or get their bearings at night. This book uses photos of dolphins to show their everyday life. Mating and childrearing are important aspects of dolphins' lives; the photography has captured it all on film. Their enemies include sharks, killer whales, fishing nets and human hunters. The Marine Mammal Protection Act of 1972 made it illegal to hunt or harass any mammal in U.S. waters. However, pesticides, heavy metals and PCB's that pollute our oceans may be the cause of beachings by some sea mammals. The Delphinidae family of which dolphins are a part, includes many other oceanic mammals, such as pilot whales, killer whales, sperm whales, beluga whales, and harbor porpoises. The text gives brief descriptions of each. The book includes a bibliography of further reading, internet sites, and index. This is an excellent volume in the "Animal Close-up" series. 2004, Charlesbridge, Ages 5 to 12.