My primary research interests are atmospheric deposition, terrestrial nutrient
processing and export, aquatic nutrient cycling, and primary productivity. I have concentrated
primarily on terrestrial and aquatic systems in the basins of Atlantic estuaries and in the
Amazon River floodplain, but I have also investigated periphyton and macrophytes as well as the benthic microflora of carbonate sands on coral reefs. Processes examined are atmospheric deposition, historical land use changes, stream chemistry, nutrient processing in streams and estuaries, and primary productivity. Common tools are GIS, remote sensing, water chemistry monitoring, and hydrochemical modeling.