SUMMARY

DOC in the Everglades

- Land use and water movement control types of DOC throughout the Everglades.

- Surface water DOC concentrations decrease from north to south in the northern Everglades.

- Northern samples are more aromatic in nature than samples from the south.

DOC-Mercury Interactions: Field Observations

- DOC concentrations and aromatic carbon content are lower at locations where methyl mercury is high.

- DOC exerts a strong influence on the photochemical reactivity of mercury.

DOC-Mercury Interactions: Laboratory Results

- Lab experiments indicate strong interactions between DOC mercury and mercuric sulfide.

- The strength of the interactions is strongly dependent on the properties of organic matter, especially organic sulfur.

- F1 samples are more reactive with mercury than 2BS samples.

Implications and Significance of Mercury-DOC Interactions

- Standard geochemical models are inadequate in predicting reactivity of mercury in the presence of DOC from the Everglades.

- Strong interactions between Hg and DOC could affect the bioavailability and methylation of mercury.

- Increased water flows in the conservation areas may change DOC-mercury interactions throughout the Everglades.

- Changes in DOC may effect other water quality issues related to DOC interactions such as disinfection byproducts in drinking water.