The high Antarctic Weddell Sea is inhabited by several thousands ofspecies. Trophic interactions between these organisms are the major bioticstructuring force of this complex ecosystem. Therefore, a first step towardsunderstanding and modelling of the dynamics of this system is to analyse"who eats whom". The complexity of the system requires a somewhatreductive approach, as species have to be organized in functional groups inorder to identify the major pathways of trophic flow. Information on trophicrelations is available from own investigations and from the literature. Bycombining these data with information on trophic levels based on isotopicsignatures, we can estimate a number of food web characteristics, e.g. foodchain length or predator-prey ratio. This is a significant step forward towardsa realistic mass-balanced model of trophic flows within the Weddell Seaecosystem.