Dioxins and furans linked to reproductive impairment in wood ducks

A wetland in central Arkansas was contaminated with polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and because the area was a major waterflow habitat, we studied the effects of the contamination on nesting wood ducks (Aix sponsa) during 1988-90. Residues in wood duck eggs, based on toxicity equivalency factors (TEFs) for combined compounds, ranged from 0.2 to 611 parts per trillion (ppt) wet mass (70% were the toxic isomer 2,3,7,8-tetrachlorodibenzo-p-dioxine [tetraCDD]) and were 50 times higher in eggs from near the point source than from an uncontaminated reference site 111 km away. Nest success, hatching success, and duckling production were suppressed (P 20-50 ppt. Wood ducks were sensitive to dioxin and furan contamination, and we recommended it as an indicator species for monitoring biological impacts from these contaminants. 26 refs., 4 tabs.