RECOMMENDED USES OF EMPIRICALLY DERIVED, SEDIMENT QUALITY GUIDELINES FOR MARINE AND ESTUARINE ECOSYSTEMS

Sediment quality guidelines (SQGs), based upon empirical analyses of m atching chemical and biological data, have been developed for many pot entially toxic substances. The predictive abilities and recommended ap plications of two sets of guidelines, ERLs/ERMs and TELs/PELs, are dis cussed in this paper. The SQGs were intended as informal (i.e., non-re gulatory) benchmarks to aid in the interpretation of chemical data. Lo w-range values (i.e., ERLs or TELs) were intended as concentrations be low which adverse effects upon sediment-dwelling fauna would be expect ed only infrequently. In contrast, the ERMs and PELs represent chemica l concentrations above which adverse effects are Likely to occur. Eval uations of the reliability and predictive ability of the SQGs indicate they can be used effectively to assess the quality of soft, aqueous, sedimentary deposits. Specifically, the SQGs can be used to classify s ediment samples with regard to their potential for toxicity, to identi fy contaminants of concern, and to prioritize areas of concern based o n the frequency and degree to which guidelines are exceeded. Toxicity and bioaccumulation tests, toxicity identification evaluations, and be nthic community assessments provide complimentary information for asse ssing sediment quality.