Environmental Aspects of Dredging in Estuaries

Salt marsh estuarine environments along the Intracoastal Waterway of the southeastern Atlantic coast were studied to determine the environmental effects of dredging in these areas. The study dealt with the chemical response of salt marsh seidments to the deposition of dredge materials and with the water quality response to dredging and deposition of sediments in a salt marsh estuarine environment. After the initial destruction of the salt marsh plants due to spoil deposition, the rate of reequilibration of the marsh sediments to their original state (suitable for revegetation) is greatly dependent on the depth of the dredge spoil deposit. In natural and relatively unpolluted areas, dredging has no significant effects on water quality when either diked or undiked confinement techniques are used. In polluted areas in marine environments, water quality impairment caused by dredging activites do not necessarily bear any simple relation to the composition of the sediemtns to be dredged.