'Let's Protect Our Sea' focuses on the coast and seas of this part of the world, the East Asian Seas region. In all the countries of this region most people live near the coast and depend on the sea for their everyday life. We wrote this book to guide you and to give you ideas on how to look after your coast and seas. The coast and the sea are part of your natural environment. Just like other things in your life (a radio, a television, a bicycle or a car), if you take care of them, they will not get damaged and you can use and enjoy them longer. The scientists give this big words and call it "sustainable utilisation ". It means to use something wisely and carefully so it lasts and continues to work or provide for you. The book will also show you how you can start contacting other young people in different parts of your country or even in other countries of the East Asian Seas region through a Youth Environment Network. "Network" and "networking" are two more big words, but when you write, telephone or talk to other young persons about the same things (for instance, the coast and the seas) and exchange ideas and information, you start a network between your friends and you are networking.