Trace metal concentrations in aquatic invertebrates: why and so what?

All aquatic invertebrates take up and accumulate trace metals whether essential or not, and subsequent body concentrations of trace metals show enormous variability across metals and invertebrate taxa. Accumulated metal concentrations are interpreted in terms of different trace metal accumulation patterns, dividing accumulated metals into two components - metabolically available metal and stored detoxified metal. Crustaceans are used as examples of different accumulation patterns that will have a general applicability to all aquatic invertebrates. Toxicity is related to a threshold concentration of metabolically available metal and not to total accumulated metal concentration. The significance of accumulated metal concentrations is discussed in terms of the biological significance, including the attempted recognition of a high or low concentration, and of the applied use of aquatic invertebrates in biomonitoring programmes assessing geographical and temporal variation in trace metal bioavailabilities in aquatic systems. (C) 2002 Elsevier Science Ltd. All rights reserved.