Stat: 100 feet: At nearly 100 feet in length, blue whales are the largest animal ever known to have existed on Earth.

Story: Blue whales are big but they're not invulnerable, often falling victim to strikes by ships in the northern India Ocean. Asha de Vos, a Pew marine fellow who founded Sri Lanka's first marine conservation research and education organization, tells us about the beauty of blue whales and their importance to the health of the ocean.