Samples collected in the framework of a study to understand implications of these environmental changes for coastal Southern Ocean ecosystemsThis study looked at benthic food web structure on the coasts of Adélie Land during an event of unusually high sea ice cover (i.e. two successive austral summers without seasonal break-up). Using time-tested integrative trophic markers (stable isotope ratios of carbon, nitrogen and sulfur) and state-of-the-art data analysis tools (Bayesian ecological models), exploring feeding habits of benthic macroinvertebrates communities. In total, 28 taxa spanning most present animal groups and functional guilds were investigated.