White sharks and tuna travel for thousands of miles before returning to the same hot spot just as salmon do when they return to the same stream. These journeys are the marine equivalent of wildebeest migrations that take place on the Serengeti plain in Africa.

Sharks are being driven to extinction because people want to eat their fins and their flesh.

I remember being in strong physics, physiology and biology classes.

Human technology has made it to Mars. We are transmitting gorgeous pictures from it. Yet we have not explored our own planet. Two-thirds of it is covered with oceans that are still mysterious places.