Interpretation of Metal Concentrations in Estuarine Sediments of Florida Using Aluminum as a Reference Element

Abstract

Metal contamination of estuarine sediments is an increasing problem in Florida and elsewhere as urbanization extends into previously undeveloped areas. Effective estuarine management practices require scientifically valid tools to assess the extent of estuarine contamination. Interpretation of anthropogenic metal contributions has been hampered by the fact that natural metal concentrations in sediments vary by orders of magnitude in different sediments. Normalization of metal concentrations to a reference element, aluminum, appears to be a promising method for comparing estuarine sediment metal concentrations on a regional basis. In this paper we describe an interpretive method based on the relationship between sediment metals and aluminum derived from statewide data on natural estuarine sediments in Florida. We show how the method can be used to interpret metal concentrations with an example using data from the Miami River and Biscayne Bay.