Avoidance response of the estuarine amphipod Eohaustorius estuarius to polycyclic aromatic hydrocarbon-contaminated, field-collected sediments

Amphipods (Eohaustorius estuarius) were placed in two-chamber containers wi th different combinations of three contaminated sediments and a control sed iment, and their distribution was determined after 2 or 3 d. Amphipods avoi ded the sediment with the highest PAH contamination and one of two sediment s with moderate PAH concentrations. In the moderately contaminated sediment avoided by amphipods, the (avoidance) response was more sensitive than mor tality as a biological indicator of unacceptable sediment contamination (ov er the 2-3-d exposure). The avoidance response in this case likely represen ts an early indication of potential mortality from sediment exposure. Popul ation levels of amphipods in moderately to heavily PAH-contaminated sedimen ts may be influenced by a combination of avoidance behavior and toxicity/le thality.