Dolphins are mammals that breathe air, give birth to live babies that drink milk, and are carnivorous fish and squid eaters. They live in oceans where the temperature is usually cold, there is lots of seaweed and sand, and deep waters with many other fish. Dolphins are threatened by being killed for their blubber and oil by fishermen. Efforts to help dolphins include placing them in protected areas like SeaWorld and wildlife centers, as well as symbolic adoption programs and defender memberships.