Individual clams and oysters were exposed to the toxic dinoflagellate, K. brevis at a bloom concentration of 5?¡Á?105 cells¡¤L?1 for eight days and then transferred to filtered water for depuration. Individuals were sampled periodically to determine depuration rates. Concentrations of brevetoxins (and/or their metabolites measured as PbTx-3 equivalent) in tissues were determined using an Enzyme Linked Immunosorbent Assay (ELISA). After five days of exposure, brevetoxin levels in tissues of both species reached concentrations well above the regulatory limit of 800?ng?g?1 (Pb-TX3 equivalent). Averaged concentration of brevetoxins in clams was 1000?ng?g?1, while the oysters averaged 1986?ng?g?1. After two weeks of depuration, tissue concentrations in both species were below regulatory levels with clams averaging ¡«204?ng?g?1 and oysters averaging ¡«437?ng?g?1. Toxins (or their metabolities) remained detectable in both clams (139 days) and oysters (82 days) for the duration of the experiment.