Tr. Barber et al., USING A SPIKED SEDIMENT BIOASSAY TO ESTABLISH A NO-EFFECT CONCENTRATION FOR DIOXIN EXPOSURE TO THE AMPHIPOD AMPELISCA-ABDITA, Environmental toxicology and chemistry, 17(3), 1998, pp. 420-424
A recent study conducted by the National Oceanic and Atmospheric Admin
istration (NOAA) reported a highly significant correlation between 2,3
,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) concentrations and amp
hipod (Ampelisca abdita) mortality in sediment samples collected from
the lower Passaic River and Newark Bay. However, there is a paucity of
data regarding the potential effects of 2,3,7,8-TCDD on benthic inver
tebrates under controlled laboratory exposures. In this study, 10-d wh
ole-sediment bioassays using the marine amphipod A. abdita were conduc
ted on spiked sediment samples representing a range of 2,3,7,8-TCDD co
ncentrations (0-25 mu g/kg dry weight). No effects on survival or grow
th relative to controls were observed at any test concentration. The h
ighest 2,3,7,8-TCDD concentration reported from the NOAA study was 0.6
2 mu g/kg. Therefore, the lack of 2,3,7,8-TCDD toxicity in this study
indicates that the mortality observed in the NOAA study was probably d
ue to factors or chemicals other than 2,3,7,8-TCDD. This study demonst
rates the utility of spiked sediment bioassays in evaluating cause and
effect relationships between sediment contamination and benthic inver
tebrate mortality.