Bioturbation, sedimentation and sediment-water exchanges

Abstract A number of pollutants are associated with the particulate matter in river, estuary and coastal environments. Following cessation of a contaminant discharge, a question sometimes arises as to what degree and over what time period deposited sediments may be a pollutant source to the indigenous water column. In addition to chemical and biological reactions and exchanges, this assessment depends on at least three physical processes, viz., sedimentation rate in burying polluted sediments, bioturbation in reconstituting polluted sediments back to the sediment-water interface, and bottom sediment-water column exchanges. The theoretical formulation and solutions are given for these physical processes, and the theoretical results are applied to mercury observations from sediment cores in Bellingham Bay, Washington, USA