The present dataset has been used to assess how macrobenthic communities vary depending on (i) the type of dune, (ii) the position within the dune and (iii) the season. It has been combined with a biological traits dataset [Robert Alexandre Elie, Quillien Nolwenn, Bacha Mahmoud, Caulle Clémence, Nexer Maëlle, Parent Briz, Garlan Thierry, Desroy Nicolas (2021). Biological traits of macroinvertebrates associated with subtidal sandy beforms. SEANOE. https://doi.org/10.17882/80785] and results from this analysis have been published in Marine Pollution Bulletin in 2021 [Alexandre Elie Robert, Nolwenn Quillien, Mahmoud Bacha, Clémence Caulle, Maëlle Nexer, Briz Parent, Thierry Garlan, Nicolas Desroy, Sediment migrations drive the dynamic of macrobenthic ecosystems in subtidal sandy bedforms, Marine Pollution Bulletin, Volume 171, 2021, 112695, ISSN 0025-326X, https://doi.org/10.1016/j.marpolbul.2021.112695.