Sharks are beautiful animals, and if you're lucky enough to see lots of them, that means that you're in a healthy ocean. You should be afraid if you are in the ocean and don't see sharks.

Humans have always wondered the big questions, "Who am I? Where have I come from? Where am I going?" It's part of human nature. It's perhaps the underpinnings of religion.

Our job is to keep what is working intact and not destroy what we have got.

This is a living planet. Look around. Mars, Venus, Jupiter. Look beyond our solar system. Where else is there a place that works, that is just right for the likes of us? It has not happened just instantly. It is vulnerable to our actions. But it's the result of four and a half billion years of evolution, of change over time. And it changes every day, all the time. It would be in our interest to try to maintain a certain level of stability that has enabled us to prosper, to not wreck the very systems that give us life.

Knowledge is the key to making a difference.

When you are a child you learn your alphabet, your numbers, but increasingly, we must learn from the earliest stages that the highest priority has to be to maintain the world as a safe place for humankind.

We have been far too aggressive about extracting ocean wildlife, not appreciating that there are limits and even points of no return.