Studies of marine ecology have traditionally been approached through lectures and field courses devoted mainly to intertidal and inshore habitats, and it is surprising in these days of increased awareness of man's environmental impact that so little attention has been given to integrated approaches involving the whole coastal zone and including the terrestrial part, which is man's major habitat. The coastal zone has been the subject of extensive investigation, not only because of its biological diversity and accessibility, but also because of its economic and aesthetic importance to man. This book is written with the intention of providing a concise but readable account of coastal ecology for advanced undergraduates and immediate postgraduates. We have adopted a habitat-organismal ap­ proach because we believe that a knowledge of biota and major features of their environment is the best key to an understanding of both larger-scale processes, such as energy flow and nutrient cycling, and smaller-scale but equally fundamental processes, such as behavioural and physiological ecology. Examples have been selected from polar, temperate and tropical regions of the world. The breadth of the subject has dictated selectivity from sources too numerous to acknowledge individually, but we have included an up-to-date reference list for the main subjects of each chapter.