Tiger sharks are among the most feared species of sharks in the world, with a reputation for being aggressive and somewhat unpredictable. In actuality, tiger sharks are generally unaggressive and are important species for dive tourism in several areas around the world, though they are of course large predators and should be treated with respect. Tiger sharks are identifiable by their distinctive spots, which fade with age, and by their broad head and snout. The teeth of tiger sharks are distinctively shaped with a curved saw edge that are used like can openers to cut through the hard shells of sea turtles, and they are among the only shark species known to actively target seabirds as a food source. These sharks are likely important to seagrass ecosystems, as in their absence grazers such as sea turtles and dugongs can overgraze an area and degrade the habitat.