Are fecal stanols suitable to record and identify a pulse of human fecal contamination in short-term exposed shellfish? A microcosm study

International audience; In this study, the capacity of oysters to bioaccumulate fecal stanols and to record a source-specificfingerprint was investigated by the short-term contamination of seawater microcosms containing oysterswith a human effluent. Contaminated oysters bioaccumulated the typical fecal stanols coprostanol and24-ethylcoprostanol and their bioaccumulation kinetics were similar to that of the Fecal Indicator BacteriaEscherichia coli used in European legislation. Although stanol fingerprints of contaminated waterallowed the identification of the human specific fingerprint, this was not the case for oysters. This discrepancyis attributed to (i) high concentrations of endogenous cholestanol and sitostanol, responsiblefor ‘‘unbalanced’’ stanol fingerprints, (ii) different accumulation/depuration kinetics of fecal coprostanoland 24-ethylcoprostanol and (iii) the limits of the analytical pathway used. These results show that fecalstanols bioaccumulated by oysters are useful to record fecal contamination but the usefulness of stanolfingerprints to identify specific sources of contamination in shellfish currently seems limited.