Brown algae species as biomonitors of Zn and Cd at Sepetiba Bay, Rio de Janeiro, Brazil

In order to contribute to monitoring heavy metal contamination of Sepetiba Bay, Rio de Janeiro, Brazil, long term evaluation of Zn and Cd concentration was performed in two brown algae species, Padina gymnospora and Sargassum stenophyllum. In relation to Sepetiba Bay macroalgae community, these species were the most abundant in substrate cover. The algae metal concentration variation from 1990 to 1997 should be related to the inputs of metals released into the bay by industrial process of Zn production in the area. In situ uptake and release transplant experiments with Padina between Sepetiba Bay and a near uncontaminated area showed that the species could reflect the variation in metal environment availability, A lower reduction in metal concentration by plants transplanted to the uncontaminated area was observed. Analytical electron microscopy showed that the Zn in P. gymnospora from Sepetiba Bay was present as small deposits distributed in the cell walls. (C) 1999 Elsevier Science Ltd. All rights reserved.