Due to its particular characteristics, the Mediterranean Sea is often viewed as a microcosm of the World Ocean. Its proportionally-reduced dimensions and peculiar hydrological circulation render it susceptible to environmental and climatic constraints, which are rapidly evolving. The Mediterranean is therefore an ideal site to examine, in order to better understand a number of key oceanographic phenomena. This is especially true of the Ligurian Sea where, due to its geology, oceanic conditions are found close to the coast. As such, 30 years ago, an offshore time-series site provided a fresh impetus to a long history of marine biology research, which has generated a very important body of data and knowledge. This is the first volume, in a two-volume series, that summarizes this research. Across these two books, the reader will find 13 chapters that examine the geology, physics, chemistry and biology of the Ligurian Sea ? always with the goal of providing key elements of oceanography in a changing world.

It is now nine years since the first edition appeared and much has changed in marine science during that time. For example, satellites are now routinely used in remote sensing of the ocean surface and hydrothermal vents at sea noor spreading centres have been extensively researched. The second edition has been considerably expanded and reorganised, and many new figures and tables have been included. Every chapter has been carefully updated and many have been rewritten. A new chapter on man's use of the oceans has been included to cover satellites and position fixing, renewable energy sources in the sea, seabed minerals, oil and gas, pollution and maritime law. In this edition we have also referred to a number of original references and review articles so that readers can find their way into the literature more easily. As in the first edition, PSM has been mainly responsible for the text and HC for the illustrations, although each has responded to advice from the other and also from many colleagues. In this context readers should note that the illustrations form an integral and major part of the book. The text will almost certainly be too concise for many readers if they do not study the illustrations carefully at the same time. The book has been written as an introductory text for students, although it can serve anyone who is beginning a study of the sea.

Our evolution and that of all plants and animals is not thought to be due solely to the gradual accumulation of gene changes within species. Symbiosis is at the root of our being. This book is a systematic history of this emerging field and gives an account of the growth of a biological idea.