At night, oxygen is depleted at the sediment surface. Methylmercury is produced and it moves out of sediments by diffusion and with zooplankton, which seek protection in sediments during the day.	During the day, plankton produce oxygen at the sediment surface and prevent methylmercury from moving out of sediments. Plankton, which move up from the sediment surface, may bring methylmercury to upper waters.

Dissolved Organic Carbon in the Everglades
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Dissolved organic carbon (DOC) influences processes that control mercury cycling in the environment. Different DOC "teas" influence mercury in different ways.		Dissolved organic carbon is similar to tea. Plants, plant litter, detritus and peat are analagous to tea leaves. Just as different tea leaves give different types of tea, different types of organic matter give different types of DOC.
		"Everglades Teas"

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

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

How does mercury get into the fish and achieve such high levels in the Everglades?

Unlike most metals, mercury accumulates in fish through their diet. Therefore, it is important to understand the nature of the food web to fully understand the nature of the whole mercury cycle.

Figuring out Who Eats Who?

The visual approach (Gut content inspection) Diet of Everglades Gambusia Diet of Largemouth Bass

The chemical approach

(Click on graphs for larger versions.)

The combined use of visual and isotope tracing methods to unravel the complexities of the food web have allowed ACME scientists to better understand the complexities of biotic relationships in the Everglades.