This study is a part of a large research project aiming at developing an ERA tiered framework for sediment management, in the context of integrated management of contaminated sediment, site restoration and sustainable navigation. The purpose of this study is to assess sediment quality by exploring the relationships between chemical contamination and benthic community structure using classical taxonomy and functional traits approaches. During falls 2004-2005, macroinvertebrates were collected in 59 sites in the St. Lawrence River, especially in its three fluvial lakes and in the harbour zone of Montreal. Organic (PCBs, PAHs, petroleum hydrocarbons), inorganic (As, Cd, Cu, Cr, Hg, Ni, Pb and Zn) contaminants and sediments characteristics (e.g. grain size, metal-binding phases, nutrients) were measured in whole sediment. Taxonomy and functional traits of benthic macroinvertebrates in the St. Lawrence River will be used to assess the relative impact of chemical contamination and sediment characteristics applying multivariate analysis and variance partitioning. We will compare the potential of taxonomy and functional traits approaches for assessing sediment quality in comparison with chemical sediment quality guidelines classification. The preliminary results and the implication for the development of an ERA tiered framework will be discussed.