This book contains the papers presented at a NATO Advanced Research Institute on "Mediterranean Marine Ecosystems", held at Heraklion-Crete, Greece, from September 23-27, 1983. A workshop rather than a conference, it was sponsored by the Eco-Sciences Special Programme Panel, in cooperation with the Marine Science Panel. The third of its kind, it was scheduled in the framework of a project on a multidisciplinary integrated approach to the study of the Mediterranean. This Sea and the surrounding land was not only the cradle of many civilizations but is, up to the present time, one of the major world areas of marine traffic, communication and exchanges, fisheries and aquacultures, inshore human activities and ¿¿¿ pollu­ tion. To a certain degree it constitutes a gigantic natural labo­ ratory, where the fate of threatened aquatic and terrestrial eco­ systems including the human one, is tested. The Mediterranean Sea, with its geological history and present­ day geographic, hydrological and climatic conditions is believed to form an ecological entity. Important exchanges and mutual influences take place with the surrounding land area and the water masses, naturally (Atlantic, Black Sea) or artificially (Red Sea), connected to the Mediterranean. Therefore, a better and in-depth knowledge of the various ecosystems, benthic, planktonic and nektonic, neritic or pelagic, in the Western or the Eastern Basin seems to be a pre­ requisite to any action in preserving, upgrading and managing the natural resources of the area.

Ecological Factors and their Biogeographic Consequences in the Mediterranean Ecosystems.- The Mediterranean Benthos: Reflections and Problems Raised by a Classification of the Benthic Assemblages.- On the Biogeography of the Benthic Algae of the Mediterranean.- Distribution and Ecology of Endemic Elements in the Mediterranean Fauna (Fishes and Echinoderms).- Mediterranean Sea Meiobenthos.- The Deep Mediterranean Benthos.- The Eastern Mediterranean Shelf Ecosystem in Global Connexion Including some Biological and Geological Implications.- Effects of Pollution and Man-Made Modifications on Marine Benthic Communities in the Mediterranean: A Review.- The Effects of the Geological and Physico-chemical Factors on the Distribution of Marine Plants and Animals in the Mediterranean.- Environmental Control of the Mesoscale Distribution of Primary Producers and its Bearing to Primary Production in the Western Mediterranean.- Phytoplankton Production in Oligotrophic Marine Ecosystems: the Mediterranean Sea.- Deep Phytoplankton and Chlorophyll Maxima in the Western Mediterranean.- Features and Peculiarities of Zooplankton Communities from the Western Mediterranean.- The Zooplankton Communities of the Eastern Mediterranean (Levantine Basin, Aegean Sea): Influence of Man-Made Factors.- Processes of Differentiation Between Mediterranean Populations of the Super-Species Tisbe clodiensis Battaglia and Fava (1968) (Copepoda).- Evolutionary and Zoogeographical Remarks on the Mediterranean Fauna of Brachyuran Crabs.- The Impact of the Lessepsian (Suez Canal) Fish Migration on the Eastern Mediterranean Ecosystem.- Mediterranean Marine Ecosystems: Establishment of Zooplanktonic Communities in Transitional and Partly Isolated Areas.- Contributors.- Species Index.