This new book, as described in the Preface, presents a collection of contributions by several participants of the First National Congress of Marine Sciences organ­ ized by the CoNISMa. The 62 selected papers, grouped into seven sections, deal with a number of significant and current topics of marine research conducted at Mediterranean stations mostly situated along the Italian coast. The focus of each section is clearly expressed in the headings. The research sites may be conceived as "key" or focal points in the study of marine ecosystems. Indeed. the information collected transcends regional inter­ ests by promoting better understanding of the structures and processes charac­ terizing a wide area of the Mediterranean basin. The reader may easily note that in the entire book special attention is devoted to the observed changes and the ensuing diversity in time and space. Temporal diversity ranges from paleontological scales to shorter time scales. The latter is the case, for instance, with chemical species, circulation patterns, energy fluxes linking particulate matter with microbial communities, structure of food webs, bacterial, plant and animal species, etc. As to the disciplinary aspects, the majority of papers reflect a modern approach, in both conceptual and methodological terms, and a marked tendency to overcome the boundaries of specific disciplines. This applies particularly to the evaluation of intraspecific biodiversity, where methods borrowed from mo­ lecular biology are largely utilized.