The accompanying ecological research for using wind energy in the German North and Baltic Seas is part of a series of research projects in the German Government's Investment Programme for the Future. It has brought out a variety of results about possible effects on the marine environment. This book provides an overview of the state of the accompanying ecological research in Germany. The main objective of the book is to show the relevance of the new results of these research projects for the planning and permission process for offshore wind energy plants. This book was kindly supported and funded by: Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) and Jülich Research Centre The Project Management Organization Jülich (PtJ)