Estuaries as sinks for sediment and industrial waste - a case history from the Massachusetts coast

Více o knize

Many estuaries globally are experiencing sediment accumulation from landward transport, leading to issues such as harbour silting. Our research along the New England coast reveals that strong flood tidal currents transport silt and clay in near-bottom suspensions up the Acushnet estuary to New Bedford Harbour, resulting in siltation. Weaker ebb currents carry some clay back into Buzzards Bay. By integrating sedimentological and geochemical methods, we aim to understand the accumulation and dispersal of solid waste in the estuary, using the sediment column as a historical record of industrial contamination and employing industrial wastes as tracers for sediment movement. This methodology helps model the long-term impacts of oceanographic conditions on sediment dynamics and environmental contamination. Previous studies indicated that estuarine sediments contained up to one percent of combined Cu, Cr, and Zn. Our investigation focuses on the spread and rate of these metals beyond their industrial sources, as well as the distribution of organic-rich sediment from sewage discharge. We emphasize sedimentary processes, the distribution of sedimentary organic matter, and the concentrations of metals including Ag, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn.