For the five cores examined, our calculated Hg EAR's showed an increase between about 8 and 12 cm in depth. Depending on the core, the depths corresponded to sediment ages from about 20 years to about 60-180 years. In contrast, the sediments in WCA have shown a general decrease in EAR with depth. These values directly reflect high sediment accumulation rates and not high total Hg concentrations. Sulfur concentrations and speciation were determined in sediments and pore water and are only peripherally discussed in this report.
Sulfur is found to possibly influence the metal distributions in sediments.
The environment of Taylor Slough ranges from a freshwater, low sulfate environment in the north, to a brackish water, high sulfate environment in the south. Correlation is not a proof of a mechanism, but does provide an indication that sulfur may play a role on metal distributions in sediments, especially in the southern part of the slough. Except for Fe, the EF values in root tissue were lower than in leaf tissue. This difference reflects the greater concentration of most elements in root tissue relative to leaf tissue. The high EF values in general indicate that sawgrass tissue has a tendency to accumulate elements relative to the substrate within which it is growing.