Turbidity maxima in estuaries are important due to their influence on prima
ry production, pollutant flushing, fish migration and dredging, There is a
need for a better understanding of the dynamics of turbidity maxima. Result
s are given for the response of turbidity maxima and salinity in the tidal
Trent and (Yorkshire) Ouse over time scales of a semidiurnal tide to an ann
ual cycle with respect to tidal and fluvial influences. Under low fresh wat
er flow conditions sediment moves landward and the turbidity maximum is obs
erved upstream of the fresh-salt water interface. Longitudinal dispersion p
rocesses governing salinity appear to be dominated by transverse shear indu
ced effects. Suspended solids concentrations within the turbidity maximum a
re strongly influenced by tidal asymmetry and suspended solids vertical con
centration gradient effects and their associated influences, It is proposed
that the higher concentrations of suspended solids in the Ouse estuary, co
mpared with the tidal Trent, are due to the influence of the lower fluvial
discharge in the appropriate reaches. (C) 1999 Elsevier Science Ltd. All ri
ghts reserved.