Knowledge is the key to making a difference.

The Arctic is a place that historically, during all preceding human history, has largely been an icy realm with an impact on ocean currents. That, in turn, influences the temperature of the planet. The Arctic is now vulnerable because of the excess carbon dioxide in the atmosphere, with a rate of melting that is stunning.

Any astronaut can tell you you've got to do everything you can to learn about your life support system and then do everything you can to take care of it.

Since I began exploring the ocean in the 1950s, 90 percent of the big fish have been stripped away. Tuna, sharks, swordfish, cod, halibut, you name it, the numbers have just collapsed. Also, about half of the coral reefs are gone, globally, from where they were just a few decades ago.

We must protect our ocean as if our lives depend upon it, because they do.

By the end of the 20th century, up to 90 percent of the sharks, tuna, swordfish, marlins, groupers, turtles, whales, and many other large creatures that prospered in the Gulf for millions of years had been depleted by overfishing.

The sudden release of five million barrels of oil, enormous quantities of methane and two million gallons of toxic dispersants into an already greatly stressed Gulf of Mexico will permanently alter the nature of the area.