Since larger yellowfin tuna travel in large groups with the dolphins, fisherman ended up killing the dolphins when surrounding the tuna with nets. Since 1990, a tuna boycott forced the tuna industry to purchase tuna caught on boats that fished in areas where there were no dolphins. Flipper Facts Dolphins are warm-blooded mammals that have hair, produce milk, and breathe air like we do. Dolphins do not sleep. They take short cat-naps while floating on top of the water.
Porpoises are different, they have no snouts.
If knocked unconscious, they will suffocate. Killer whales and man are the dolphin's only enemies. Many tribes around the world worship the dolphin and consider it sacred. The bottle-nosed dolphin is the most common marine mammal found in Texas coastal waters. Some dolphins were trained by the military to search for mines at sea.