|Multidisciplinary study of trophic diversity and functional role of amphipod crustaceans associated to Posidonia oceanica meadows|
Michel, L. (2011). Multidisciplinary study of trophic diversity and functional role of amphipod crustaceans associated to Posidonia oceanica meadows. PhD Thesis. Université de Liège: Liège. xi, 261 pp.
Posidonia oceanica is the most abundant seagrass of the Mediterranean Sea. It can cover extensive areas with monospecific formations, called meadows. These meadows, whose extent is estimated to about 40,000 km2, are critical features of the Mediterranean coastal zones. Moreover, they shelter important biomass and biodiversity of vagile invertebrates. Among these invertebrates, amphipod crustaceans are, alongside gastropod mollusks and polychaete annelids, one of the dominant groups. Amphipods are key-features of other temperate seagrass systems. As they are generally primary consumers, they are important in the transfers of organic matter from producers to higher rank consumers. In addition, their grazing activity on the epiphytes that grow on the seagrasses influence the dynamics of the epiphytic cover, and therefore the functioning of the whole meadow as an ecosystem. However, the situation in Mediterranean Posidonia oceanica meadows is still unclear. In particular, several lacks of information limit the comprehension of actual trophic ecology of amphipods, and of the impact of their feeding activity on the meadow functioning. In this context, the main goal of this work was to enhance the knowledge of the trophic diversity and the functional role of amphipods associated to Posidonia oceanica meadows. To achieve this, we structured our research in three main tasks. For each of these tasks, we chose Calvi Bay (NW Corsica, France) as study site, and all sampling and experimentation was undertaken from the STARESO research station (University of Liège).