This book aims to report possible applications of seaweeds in agriculture as well as the composing ingredients of nutritional value and therapeutic properties against oxidative stress. The information set provided in this book comes from very recent scientific results obtained by research groups of several countries. This information set is useful not solely for the academic community (undergraduate or graduate students, staff and faculty personnel), but also to those individuals involved somewhat with the agricultural, commercial and medical business of seaweeds. The contributing authors are renowned scientific leaders in the field. This feature associated with the new type of information provided in this book contributes significantly to the high-quality of this publication.