The bestselling I Wonder Why series has the answers to all the questions you’ve ever wanted to ask about the natural world, history, space, and more!Which bird flies underwater? Is the Red Sea really red? How deep is the ocean? Learn the answers to these questions and more in I Wonder Why: The Sea is Salty, a fascinating question-and-answer book all about seas and oceans. Award-winning children's author Anita Ganeri makes learning about the natural world fun with her accessib