PH11 Bioaccumulation and Biotransformation of POPs
Exhibit Hall
8:00 AM - Thursday, 13 November 2003
(PH115) Pesticide BSAFs Derived from Multiple Experimental Scales – Lake Apopka, Florida.
Marzolf, E1, Conrow, R1, Coveney, M1, Lowe, E1, Mace, L1, Gross, T2, Sepulveda, M2, 3, Grosso, J2, 3, Schell, J4, 1 St. Johns River Water Management District, Palatka, FL, USA2 U.S.G.S. Florida Integrated Science Center, Gainesville, FL, USA3 University of Florida, Gainesville, FL, USA4 BBL Sciences, Tallahassee, FL, USA
ABSTRACT- On going programs at the St. Johns River Water Management District convert agricultural lands back to wetlands. In 1998, at a restoration area on the north shore of Lake Apopka, the conversion resulted in a large influx of migratory birds to recently flooded fields. Over a 4-month period in the winter of 1998-1999, hundreds of fish-eating birds, primarily American white pelicans died. Given the decades of agricultural use with persistent organochlorine pesticides (OCPs), these compounds were investigated as a possible causal agent. Toxaphene, dieldrin and DDT (and its metabolites) were the most ubiquitous OCPs found in the muck soils. Previous food web accumulation modeling based on biota-sediment accumulation factors (BSAF) did not predict acute bird mortality. Subsequently, site-specific BSAFs were determined from a variety of experimental conditions and field scale measurements for multiple OCPs and species (e.g. mosquitofish, tilapia, bluegill, crayfish). In 700 L experimental tanks, BSAFs for mosquitofish tended to decline slightly, but not significantly, with increasing soil/sediment organic carbon content (range 1.5 - 48%). BSAFs varied between OCPs and species, but were within ranges found in the literature. The failure of models to predict acute mortality does not appear related to incorrect BSAFs.
Key words: chlorinated, apopka, pesticide, bsaf