Fate of Trace Metals in the Sediments of the New York Bight. Environmental Sciences Division Publication No. 2035

摘要

The available measurements of trace metal concentrations in the sediments of the New York Bight (NYB) were assembled with the aim of understanding their fates in this humanly impacted coastal system. The raw data assembled included more than 8000 determinations of 16 trace elements from 1000 stations in the Bight. Where available, additional relevant data such as grain size, total organic carbon (TOC), and loss on ignition (LOI) were also assembled. The major sources of trace metals to the Bight are polluted dredged material, sewage sludge, and wastewaters delivered by barges, rivers, runoff, and atmospheric precipitation and deposition. Whatever the source, it is clear that many of the trace metals are sequestered on particles and removed to the sediment rapidly. Shelf transport may occur before and after deposition. In the Bight apex, which includes the dumpsites, there is a very high (often > 0.9) correlation of the concentrations of each of the trace metals examined (Zn, Cr, Cu, Pb, Ni, Fe, Hg, Cd) with measures of organic matter concentrations in the silt-plus-clay percentage of the sediment. The best estimates for trace metal fluxes to the sediment suggest that sewage sludge may be the most important source, though all three sources (sewage sludge, dredged material, and airborne particulates) have fluxes that are of a similar order of magnitude (10 exp 8 g/y). (ERA citation 08:003018)