Bioaccumulation and Food Chain Transfer of Polycyclic Aromatic Hydrocarbons and Heavy Metals: A Laboratory and Field Investigation.

The extent to which heavy metals and Polycyclic aromatic hydrocarbons (PAH) may be transferred up the food chain from sediments to benthic invertebrates and then on to fish species was examined using both laboratory and field techniques. PAHs were shown to bioaccumulate in a chironomid invertebrate (chironomus riparius) to relatively high levels depending on the specific compound. Accumulation in a fish specie (Lepomis macrochirus) that was fed contaminated chironomids was found to be generally low. Mobilization of PAHs from sediments into water was affected by benthic organisms enhancing the bioavailability of these contaminants to other organisms. In field studies, certain benthic invertebrates and abiotic sediment components were also shown to accumulate heavy metals. This metal accumulation persisted even when metal concentrations in the water were diminishing.