ABSTRACT
This chapter examines the physical, chemical, and biological changes in estuaries ascribable to dredging and dredged-material disposal. The disposal of dredged spoils in estuarine and marine waters accounts for most of the materials dumped in the environments. Sub-bottom containment involves the capping of contaminated dredged spoils with clean sediments to minimize the reentry of chemical pollutants into the water column. Most investigations of dredging and dredged-spoil disposal operations focus on environmental impacts while ignoring or downplaying ecological benefits. The species composition of a benthic community at a dredged site or a spoil disposal location is most likely to be altered by the release of toxic contaminants from the sediments or by acute changes in sediment type. Dredging action, in addition to the open-water disposal of dredged sediment, impinges on the water quality of estuaries via the generation of turbidity, and the redeposition of the dredge-induced suspended sediment can impact benthic communities.
