Thanks to the combination of various measures of diversity (structural diversity, functional diversity and isotopic diversity) the present study investigates the spatio-temporal dynamic of the benthic ecosystem of bedform areas. Results suggest that the macro-scale distribution of species is mainly driven by the migration rate of bedforms (sandbank, barchan dune and transversal dune) which changes the sediment grain size and reduces macrobenthic diversity. Conversely, the high frequency of migration events homogenizes macrobenthic communities between the troughs to the crest of bedforms. The benthic community structure also changes between seasons due to the massive recruitment of juveniles. However, if species identity and structural diversity change it have little consequences on the general ecosystem functioning. Especially, the benthic food web of bedforms areas appears very stable with limited variations, both in space and time. It displays very simplistic trophic pathways, and the present study confirms the major role of Phytoplankton blooms (and especially Phaeocystis) in sustaining the benthic food web. As bedform areas are targeted for the installation of offshore windfarms, this study will provide a sound scientific basis for future impact assessments.