Cores from marshes along the southwest shore of Lake Erie were ²¹⁰Pb age-dated and analyzed for heavy metal and pesticide pollutants. The North Marsh is directly affected by agricultural run-off, while the West Marsh has been diked since 1978. Since marshes can act as sinks for metal, pesticides, and suspended solids, the chemistries of the marshes were expected to differ. However, concentrations of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn did not differ. Metal accumulation within each marsh was different for every metal studied except Ni. This was also true for accumulation averages from background (pre-1978) and recent deposits (1979-1997), which indicate the diking of the West Marsh has had a significant impact on the metal accumulation. Previously used pesticides, which have been banned for many years, were also found in both marshes. However, pesticide concentrations are higher in the agriculturally impacted marsh.