Lake Okeechobee

Reddy KR, Flaig E, Scinto LJ, Diaz O, Debusk TA (1996) Phosphorus assimilation in a stream system of the Lake Okeechobee. J Am Water Resour Assoc 32 901-915... 

Heinz, G.H., Percival, H.F., and Jennings, M.L. (1991). Contaminants in American alligator eggs from Lake Apopka, Lake Griffin, and Lake Okeechobee, Florida. Environmental Monitoring and Assessment 16, 277-285. 

The Belle Glade site, located southeast of Lake Okeechobee in south-central Florida, illustrates some of the problems that can develop with acidic-waste injection when carbonate rock is the confining layer. Contributing factors to the contamination of the aquifer above the confining zone were the dissolution of the carbonate rock and the difference in density between the injected wastes and the formation fluids. The injected waste was less dense than the groundwater because of its lower salinity and higher temperature.172... 

Soils. Black muck, developed from organic sediments from aquatic vegetation, occurs within a narrow belt bordering the southern shore of Lake Okeechobee. It contains some silt and clay and is dense and sticky when wet when dried it shrinks, cracks and crumbles into a granular mass. Most of this muck is underlain by brown, fibrous sedge peat resting on bedrock. 

Examples of anthropogenic phosphate minerals are shown in Figure 9.14 (Harris, 2002 University of Florida). Figure 9.14a shows patina of black, poorly crystalline apatite on the surface of an oyster shell located near the bottom of an early American mound, which once served as a refuse pile (about 5,000 YBP). Bones of fish and other animals were discarded in the pile and became the source of phosphorus that precipitated on the nnderlying shell. Note that oyster shells are composed of calcium carbonate, npon which phosphate readily adsorbs and precipitates (scale bar = 5 mm). Figure 9.14b shows vivianite as precipitate on an aggregate from stream sediment near Lake Okeechobee, Florida, collected a short distance downstream from where a dairy barn floor routinely flushed manure. Soils and stream sediments in the area are naturally low in phosphorus (scale bar = 1 mm). 

FIGURE 9.14 Patina of black, poorly crystalline apatite on the surface of an oyster shell located near the bottom of an early American mound (a), and vivianite as precipitate on an aggregate from stream sediment near Lake Okeechobee, FL, collected a short distance downstream from where a dairy bam floor routinely flushed manure (b). (From Harris, 2002.)... 

In Lake Okeechobee, Elorida, Reddy and Eisher (1991) estimated that under normal wind events, the resuspension flux of soluble phosphorus can account for approximately 6-18 times the diffusive flux. In comparison, resuspension of loosely bound, organically rich sediments into the water column was found not to be a major factor for delaying the recovery of shallow Danish lakes (Jeppesen et al., 2003). However, the resuspension of nutrient-enriched benthic sediments (accumulated during eutrophication process) along with the diffusive flux can result in the release of nutrients supporting phytoplankton productivity and delay the overall recovery process. 

Moore, P. A. and K. R. Reddy. 1994. Role of and pH on phosphorus geochemistry in sediments of Lake Okeechobee, Florida. J. Environ. Qual. 23 955-964. 

Reddy, K. R. and M. M. Eisher. 1991. Sediment resuspension effects on phosphorus flux across the sediment-water interface laboratory microcosm studies. In Lake Okeechobee Phosphorus Dynamics Study Biogeochemical Processes in the Sediments. Volume V. Einal Report submitted to South Florida Water Management District (Contract No. 531-M88-0445-A4), West Palm Beach, FL. 

Reddy, K. R., O. A. Diaz, L. J. Scinto, and M. Agami. 1995. Phosphorus dynamics in selected wetlands and streams of the Lake Okeechobee Basin. Ecol. Eng. 5 183-208. 

Brezonik, P. L. D. R. Engstrom, 1998. Modern and historic accumulation rates of phosphorus in Lake Okeechobee, Florida. J. Paleolim. 20 31-46. 

Sedimentary matter in many lakes tends to be rich in organic matter. A significant example of accumulation of such black mud is the large but shallow Lake Okeechobee in south-central Florida. This lake has an area of 1,750 km and a maximum depth of about 4.5 m below mean sea level. Figure 27.2 shows the thickness contours of the mud deposit. The volume of mud is estimated to be about 193 X 10 Such muds can be the primary carriers of sorbed chemicals that... 

Fig. 27.2. Lake Okeechobee in south-central Florida and contours of black mud thickness in cm...

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