A sharp, gray fin pokes above the ocean's surface and races forward. It's a great white shark--the terror of the sea. While these sharks have attacked humans in the past, usually it's because the sharks are mistaking people for their natural prey, seals. Because of this, many sharks have received a bad reputation, even though 80 percent of shark species could never hurt humans. Humans are actually more dangerous to sharks, as people are disrupting sharks' habitats, hunting their prey and even hunting sharks themselves. Some shark species are in danger of extinction. Learn more in this edition of Nature Watch.