show Abstracthide AbstractAlthough studies have investigated the presence of several bacterial species in Great Lakes sediments, as of today, no studies have been designed to qualitatively and quantitative investigate the overall diversity of bacterial communities associated with Great Lakes sediments. Therefore, a severe dearth of knowledge regarding geographic distribution of most bacterial species within Great Lakes sediments exists. This knowledge is needed to establish information on the functional diversity of Great Lakes sediment bacterial communities. Furthermore, this knowledge will allow for a better understanding of the relationship between environmental factors and ecosystem functions and of the role sediment bacteria play in benthic food webs and disease ecology of the Great Lakes. To this end, the aim of this study is to use 16S ribosomal RNA (rRNA) gene barcoded pyrosequencing and the community fingerprinting method terminal restriction fragment length polymorphism (T-RFLP) to characterize the bacterial communities associated with Great Lakes sediment from 13 locations in four of the Great Lakes.