Macrobenthos assemblages are widely used as indicators of environmental changes, as they integrate environmental changes due to their low mobility at the adult stage and rather long life expectancy. Their use is of particular importance in regulatory assessments of marine water quality status and environmental impact assessment studies. However, the prevalence of a complex life cycle with a dispersive larval stage among benthic invertebrates complicates the correlation between local environmental conditions and local assemblages.

For instance, larval dispersal by unsteady ocean flows potentially reshapes species spatial distribution and population structure at each reproduction. Such redistribution of individuals at regional scale is frequently observed in the micro-tidal Mediterranean Sea where variable meterological forcings dominate.

Hence, it appears essential to debias observations of macrobenthos assemblages from such a blurring effect. Moreover, macrobenthos assemblages tightly interact with meio- and microbial-assemblages, particularly in sedimentary environment where organic matter accumulation is a dominant driver of benthic diversity. To this end, a series of complementary research activities have been engaged in the LECOB during the previous period and will be continued, which involves benthic assemblage observations (long-term time series and distribution mapping), the evaluation and development of biotic indices, the characterization of the "resource-communities" eco-geochemical feedback loops and the evaluation and development of regional connectivity hindcasts.