Tidal Variations of Heavy Metal Concentrations in the Hackensack River, New Jersey, USA
R. Miskewitz, T.L. Su, R.I. Hires, K. Dimou, G.P. Korfiatis
As part of the NJ Toxics Reduction Work Plan for NY/NJ Harbor a targeted study was conducted to assess the variation over a tidal cycle of cadmium, lead, and mercury concentrations in the Hackensack River, New Jersey, USA. Metals concentrations collected at 4 stations were compared to simultaneous hydrodynamic measurements. A large increase in all three metals was observed during the last stages of the ebb tide and remained elevated through a significant portion of the flood tide. This increase corresponds, in general, to higher suspended sediment concentrations. These results point to the need to develop sampling strategies for estuaries, which account for both spatial and temporal water quality variability.