Within the Southern Ocean, amphipods have achieved a conspicuous ecological radiation which gave rise to the development of numerous feeding strategies. The aim of this study is to apply the carbon and nitrogen stable isotope ratio methodology to delineate the trophic relationships involving benthic amphipods in the eastern Weddell Sea food webs. The interest of the isotope technique relies upon the direct relationship between the carbon ( super(13)C/ super(12)C) and nitrogen ( super(15)N/ super(14)N) stable isotope ratios of the animal tissues and its diet. Our results demonstrate the efficiency of the isotope ratio method to distinguish species displaying different feeding strategies. The large range (from -28 to -19.5ppt for carbon and from 5.8 to 12.9ppt for nitrogen) of isotopic ratios attests the wide spectrum