Bull. Environm. Contain. Toxicol. 24,364-368 (1980) Chlordecone (Kepone) Accumulation on Estuarine Plant Detritus J. E. Drifmeyer 1., C. L. Rosenberg 2, and M. A. Heywood 1 1Department of Environmental Science, University of Virginia, Charlottesville, VA 22903 USA, 2Virginia Institute of Marine Science, Gloucester Point, VA 23062 USA This research investigated accumulation of Kepone on decomposing estuarine macrophyte detritus - an important energy sourceat the base of many estuarine food webs. After completing growth, plant tissues including the marsh grass utilized in this research, become senescent and decompose to form detritus. Concomitant with changes in organic and inorganic composition, detritus particles are reduced in size from an entire leaf or stem, down to particles several microns in diameter. This decreasing particle size and corresponding increasing surface area, along with a metabolically-active microbial decomposer community, an ion-exchange capacity, and suspension in water of changing ionic strength make detritus particles almost ideal sites of sorptionreactions. For example, accumulation of DDT on detritus particles and in detritus-consuming fiddler crabs, Uca pugnax, was reported from a Long Island marsh (ODUM et al. 1-96~). Recently the accumulation of a variety of anthropogenic pollutants on detritus has been reviewed (ODUM & DRIFMEYER 1978). Kepone is transfered "from particulate or food web processes to higher trophic levels with relatively efficient mechanisms for biological magnification..." (NRC 1978).SALEH et al. (1978) noted an association of Kepone with colloidal and particulate matter, while BOURQUIN et al. (1978) observed increased Kepone levels in sediments and detritus relative to concentrations in water. Important species including: oysters Crassostrea vir~inica, mysids Mysidopsis bahia, grass shrimp Palaemonetes pu~io, sheepshead minnow Cyprinodon varie~atus, and spot Leiostomus xanthurus accumulate Kepone from both water and items in their diets (BAHNER et al. 1977). A variety of estuarine fauna far downstream of the source of contamination have been found to contain Kepone in excess of 1 ppm (EPA 1977). * Current Address: US Army Environmental Hygiene Agency Aberdeen Proving Ground, Maryland 21010 0007-4861/80/0024-0364 $01.00 9 1980 Springer-Verlag New York Inc.