Polychaete indicator species as a source of natural halogenated organic compounds in marine sediments

Studies of pollutant impact on the marine environment assume that organic c ontaminants are anthropogenic in origin. However, many common polychaete wo rms and sediments contain readily detectable concentrations of brominated n atural products that are often analogues of chlorinated anthropogenic: cont aminants. Both polychaetes and sediments are used extensively in environmen tal toxicology and monitoring, and the extent to which natural halometaboli tes may confound these studies is unknown. To characterize further the rela tionship among infauna, indicator species, and sedimentary halogenated orga nics, we examined sediments and infauna from a pristine habitat and animals maintained under laboratory culture for haloorganics using gas chromatogra phy/mass spectrometry. Natural haloorganics are a consistent feature of pri stine marine soft-bottom habitats, and their spatial and temporal variation correlates with the abundance of infauna that produce these metabolites. A bundant organohalogens are also present in the widespread polychaete indica tor species Capitella sp. I and Streblospio benedicti but absent from the m arine invertebrate toxicology model Neanthes arenaceodentata. Studies from the individual to the community level within the fields of ecology, toxicol ogy, and environmental chemistry could be readily confounded by failing to consider these novel animal and habitat characteristics.