This volume in the Focus on Endangered Species series (5 titles) opens with a realistic scenario (a North Atlantic right whale ensnared in ropes used by crab trappers), an introduction to the challenges whales face, and bulleted facts about commercial whaling and its impact on whale survival. Utilizing a high-low format, straightforward writing, and numerous photos, individual chapters highlight four endangered whale species: North Atlantic right, sei, blue, and gray. After relating the whale's physical characteristics, diet, lifespan, and population size, each chapter focuses on threats to these immense animals, including ship strikes, fishing line entanglement, a decrease in krill, climate change, continued commercial whaling in some areas, and orca attacks. Descriptions of conservation efforts, including the International Whaling Commission's ban on commercial whaling, add to the book's research value.