Whales, dolphins and porpoise are marine mammals that are part of the taxonomic order called cetaceans, which has 78 known species. The order is divided into baleen whales of the suborder Mysticeti, and toothed whales, suborder Odontoceti. Dolphins and porpoise are toothed whales. The Northwest Region develops and implements a variety of programs to protect, conserve, and recover cetaceans through the Marine Mammal Protection Act and Endangered Species Act.

Since cetaceans are mammals, they need air to breathe. They come to the water's surface to exhale carbon dioxide and inhale a fresh supply of air. Cetaceans have their nostrils, called blowholes, on the tops of their heads, to make breathing quicker. Muscles close the blowhole as a whale dives. When the whale surfaces, the muscles open the blowhole and stale air comes out from the lungs. This warm air vaporizes as it meets the cold air outside, creating a “blow” or “spout” that people use to locate whales.

Cetaceans use sonar, or echolocation, to find things and to navigate. They make a sound, which bounces off an object and returns to them. From this, whales can figure out the size, shape, distance, characteristics and movements of an object. Cetaceans also use sound to communicate.

Baleen whales have plates along their upper jaws used to filter food from the water. Those baleen plates are made of keratin, the same material as fingernails and hair. Baleen whales have two blow holes, and are among the largest animals on earth. Female baleen whales are generally bigger than the males.

Toothed whales have teeth and a single blowhole. The number of teeth varies by species; ranging from two in some beaked whales to 250 in some dolphins. They use their teeth for catching fish, squid or other marine life. They do not chew their food, but swallow it whole. Toothed whales are smaller than baleen whales, and many species live in pods.