Blue whales are the largest animals on the planet, but what helps them grow to the length of a basketball court? Asha de Vos explains why the size of krill make them the ideal food for the blue whale -- it's as if the blue whale was made to eat krill (and krill was made to be eaten by the blue whale). [Directed by Cognitive Media, narrated by As...

Whales have a surprising and important job, says marine biologist Asha de Vos: these massive creatures are ecosystem engineers, keeping the oceans healthy and stable by ... well, by pooping, for a start. Learn from de Vos, a TED Fellow, about the undervalued work that whales do to help maintain the stability and health of our seas -- and our pla...