The Eastern Mediterranean as a Laboratory Basin for the Assessment of Contrasting Ecosystems

The Eastern Mediterranean is the most nutrient impoverished and oligotrophic water body known. The unique feature of the Mediterranean is the presence of an eastward longitudinal trend in available nitrate/phosphate ratios, which apparently induces a west-to-east variation in the structure of the pelagic food web and trophic interactions. In this context the Mediterranean, in particular its Eastern basin, provides a platform to study hypotheses related to phosphate limitation of production and the shift between "microbial" and "classical" modes of operation of the photic food web. This work assesses our knowledge of the contrasting ecosystems of the Eastern Mediterranean on the basis of ongoing national/international programmes, from both phenomenological and modelling perspectives, and identifies the major environmental issues, on both regional and basin scales, in relation to eutrophication, pollutant transport and system health. The interdisciplinary aspects of marine ecosystems are covered, ranging from marine biology and chemistry to physical oceanography.