This paper discusses the coupling between transport processes in fine-
grained sediment beds and those in the overlying boundary layer. A rev
iew of currently available, separate bed and boundary-layer models ind
icates that they do not constitute a basis for a complete description
of these couplings. Consequently, new boundary conditions and nonlocal
transports terms for resuspension are proposed in order to obtain sat
isfactory coupling between suspended and bottom sediments. The nonloca
l transport can account both for resuspension from a finite surficial
zone of sediment and its redistribution in the boundary layer. Profile
s of total suspended matter generated with this new model resemble tho
se observed in marine environments. Application to a suspended matter
profile from the Oregon Shelf suggests that this sediment is resuspend
ed at a mean rate of about 0.4% per day to a mean height of about 3 cm
. This material is then redistributed by eddy mixing to produce a clas
sic profile that decreases with height above the bed.