Discusses the evolution, physical characteristics and behavior of marine mammals and birds and explains why many of these animals are threatened with extinction and what can be done to save them.
Presents information about the four groups of sea mammals, which include earless and eared whales, walruses, sea otters, sea cows, baleen whales, toothed whales, dolphins, and porpoises.
Illustrations and text describe the background, lifestyles, and interesting features of seals, whales, sirenians, and those that live on the edge of the sea, such as polar bears and marine otters.
