Organochlorine pesticides were extensively used
in agricultural fields after WWII, and it was not until 1987 that
EPA legislation banned sales. DDT, Toxiphene, and Chlordane are
a few examples of these compounds. Organochlorines are persistent
in soil and sediments, but transfer to the water column both as
entrained sediment and via adsorption to dissolved organic carbon
(Syracuse Research Corporation 1994). At relatively low concentrations,
invertebrate populations in both sediment and water are adversely
affected. Bioaccumulation has a detrimental impact on vertebrates
Agricultural fields no longer in production
are repositories for these pesticides. As this real estate is converted
to residential or is restored, contaminated soils are often flooded.
Remobilization of sequestered pesticides is a potential ecological
risk for the estuaries downstream, both in the immediate impact
on benthic invertebrates, but also in bioaccumulation as wading
birds feed in affected areas.
Identifying potential ecological risks as these
watersheds are developed is an essential tool for resource management.
Several agricultural fields in production prior to 1978 in the District
VI, Belle Meade and Southern Golden Gates Estates watersheds are
now owned by the State of Florida. These are potential areas of
restoration with overland sheet flow as a primary goal.