This book is prepared jointly by the Institute of Oceanology, Chinese Academy of Sciences (IOCAS, Qingdao) and A.V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of the Russian Academy of Sciences (IMB FEB RAS, Vladivostok) as an outcomeof collaboration in the field of marine ecology and biodiversity studies. It covers various topics of ecosystem research, biodiversity, biogeography, environmental safety of the East China, Yellow and Japan seas, focusing on the common problems in both countries. In this book, we have tried to cover a wide range of biological oceanographic issues and invited leading scientists to present comprehensive review papers. We hope that this book would beuseful not only by national researchers, but is of broad interest for neighboring countries and world wide.