Variability in concentrations of selected trace elements in water and sediment of six acidic lakes

Concentrations of the trace elements aluminum, cadmium, lead, manganese, and zinc were determined in water and sediments of six acidic clear-water lakes (pH 3.6–6.2) in northwestern New Jersey. Levels of aluminum, lead, and zinc in the water column were sharply elevated in the most acidic lakes, with values similar to acidified systems elsewhere. Seasonal fluctuations occurred, with lead displaying peak concentrations in all lakes during the fall sampling period. Analyses of core samples of lake sediment indicated that while lead concentrations exhibited a typical sharp increase in most recent sediments, cadmium and zinc levels in the upper layers were substantially lower than values reported for similar systems elsewhere. As expected, manganese concentrations generally decreased in the upper sediment layers in the acidic lakes, while aluminum varied dramatically between systems.