Quantifying Benthic Exchange of Fine Sediment via Continuous, Noninvasive Measurements of Settling Velocity and Bed Erodibility

C T. Friedrichs, Virginia Institute of Marine Science
G M. Cartwright, Virginia Institute of Marine Science
P J. Dickhut, Virginia Institute of Marine Science

Abstract

Benthic exchange of fine sediment has major implications for the structure and function of shelf and estuarine environments. Globally, the transport of particulate organic carbon from the land to the sea is closely associated with transport of mud (McKee et al., 2004). Fine sediment transport is particularly important to the occurrence of coastal eutrophication and to the fate and burial of pollutants because nutrients and contaminants tend to adsorb preferentially onto small particles (Lee and Wiberg, 2002). However, progress in characterizing muddy benthic exchange dynamics in the past has been slow because erosion and settling properties of fine sediment remain difficult to predict. Thanks in part to the availability of continuous, noninvasive measurements, initial results from the CoOP Multidisciplinary Benthic Exchange Dynamics (MUDBED) project strongly suggest that depositional events play a key role in perturbing bed erodibility and particle settling velocity away from more stable, biologically mediated values