Approches de la capacité trophique des écosystèmes conchylicoles : synthèse bibliographique

The different methods of estimating the trophic capacity of ecosystems cultivated by oyster farming and mussel farming are introduced by ascending order of complexity. Thus, production yields make it possible to monitor whether the size of the farmed stock is being successfully matched with the availability of food. Moreover, the study of annual production farmed stocks has made it possible to create comprehensive dynamic models that show the maximum annual production that a given ecosystem can support. These last two approaches assume the environment to be constant. The study of trophic links that can simulate growth performance of molluscs can be classified according to two criteria, (i) their level of complexity in combining biology and physics, (ii) the number biological compartments studied and simulated. The physics are most often integrated at the level of an overall assessment, with the ecosystem being considered as just a box where residual flows and average duration of stay are incorporated. Some multi-box models take into account the residual flows between different boxes and simulate by advection and dispersion the transport of particulate food. The biological laws studied are, then, the classic bio-energy laws for the farmed population: filtration, ingestion, assimilation, and respiration, making it possible to simulate output. In general, the biological compartments studied are few when the physics are complex, however, models with 10 or 30 biological compartments are studied while also considering at that time a rudimentary physics and a stable state. However, the model that combines a realistic physics with the main biological compartments and their spatiotemporal variability remains to be done.