Riedel, G. F. Academy of Natural Sciences Estuarine Research Center, friedel@acnatsci.org
Gilmour, C. F. Academy of Natural Sciences Estuarine Research Center, gilmour@acnatsci.org
Riedel, G. S. Academy of Natural Sciences Estuarine Research Center, griedel@acnatsci.org

 
REGIONAL AND TEMPORAL VARIATIONS OF THE SOURCES OF TRACE ELEMENTS TO THE PATUXENT RIVER ESTUARY
 
Dissolved As, Cd, Cu, Hg, methyl-Hg, Pb, Ni, and Zn, were measured in the Patuxent River watershed from the spring of 1995 to the fall of 1997. The sites sampled included six freshwater sites, three in the Piedmont, three in the Coastal Plain, and nine estuarine sites. Concentrations of Cd, Ni, Pb and Zn were elevated in the Coastal Plain sites compared to the Piedmont sites. Concentrations of most elements were all significantly positively correlated with river flow, while arsenic and methylmercury both showed negative correlations with river flow. Because of positive correlations for Cd, Ni, Pb, and Hg with flow, the highest concentrations of these elements are estimated to be delivered the high run-off periods from late fall to early spring. Concentrations of trace elements in the estuarine portion of the river were generally low, and consistent with mixing of relatively elevated waters in the Patuxent River and lower concentrations of the Chesapeake Bay. Interesting features include a persistent local cadmium maximum in the low salinity region of the estuary, and input of water containing high arsenic concentrations from the Chesapeake Bay in summer.
 
Day: Wednesday, Feb. 3
Time: 04:30 - 04:45pm
Location: Sweeney Center
 
Code: SS28WE0430S