Why are Washington's coastal areas and the Puget Sound important?

It never ceases to amaze me when a teacher asks a question like this. Why are any coastal areas important? Why are any Sounds important? The real question should be, What are the physical properties of coastal areas that make them important enough for educated humans to talk about? Does Washington's coastal area have properties that differentiate it from other coastal areas on the planet? I would argue that the question is searching for the wrong answer. Your teacher must have listed some properties of the area she is asking you to regurgitate, or she is trying to prompt some answer from your textbook, which may or may not be true. So, I return to the real question - what is it about coastal areas, in general, that make them important to the life on the planet, or to the well being of the human population? Is there anything that differentiates the Washington coastal area and the Puget Sound from other coastal areas around the globe?