MERCURY CONCENTRATIONS IN BENTHIC ORGANISMS FROM A CONTAMINATED ESTUARY

Parts of Lavaca Bay on the central Texas coastline are closed to fishi ng by the Texas Department of Health due to Hg contamination. This is the first report on Hg concentrations in potential prey organisms for the contaminated fish, oysters and crabs of the area. Organisms were t aken from parts of Lavaca Bay known to be contaminated with Hg and fro m a less contaminated area in nearby Keller Bay. All samples from Lava ca Bay analysed (algae, polychaetes, bivalves, crustacea, detritus and wood) were higher in mercury concentration than were similar samples from Keller Bay (typically 1-10 mu g/g vs < 0.5 mu g/g). The mechanism for mercury uptake could not be determined in this study but for orga nisms confined to the contaminated areas seemed to be largely independ ent of species, feeding strategy or life stage.