| Bottom sediment samples were taken from 97 stations along 33 cross-river transects, spaced approximately one kilometer apart, and extending from the Battery, New York (km 0) north to Haverstraw Bay (km 67). The sampling program was conducted in summer, 1997 (maximum density stratification) and fall, 1998 (near isothermal water column). The resultant longitudinal and cross-river environmental gradients show simultaneous increases and/or decreases in trace metal concentrations (Ag, Cd, Cr, Cu, Ni, Pb, Zn, and V) throughout the study area with substantial increases down river in the vicinity of NJ/NY Water Pollution Control Plants (WPCPs). Trace metal concentrations were found to be greater than those of sediment quality guidelines established for bioassay toxicity. Sewage-derived carbohydrates in bottom sediments (as cellulose and hemi-cellulose) form a major portion of total organic carbon (TCH: TOC = 131–451). Ag is found to be the most pervasive contaminant followed by Pb and Cr. The results of bivariate analysis (Spearman-Rho non-parametric pairwise correlation) indicated good correlations, at 95% confidence limit, between the studied metals. The trace metal concentrations were higher along the NJ shore, where sediments are finer. NY shore was found to be 4x sandier than the NJ shore. Sediment particle size, proximity to present locations of NY/NJ WPCPs, and river hydrodynamics were found to be the main factors controlling spatial distribution of trace metals analyzed in Hudson River Estuary surficial bottom sediments. This study has established a baseline data set (summer of 1997) for environmentally available concentration distributions of selected trace metals, which may be useful in (a) future studies of correlates of benthic species richness and dominance (population density), and (b) may ultimately lead to more effective estuarine ecosystem management or restoration alternatives. |
