Contaminants in wood stork eggs and their effects on reproduction, Florida, 1982

One egg was removed from five Wood Stork (Mycteria americana) nests at each of eight colonies in central and northern Florida in 1982. DDE and mercury were present in all eggs with concentrations ranging up to 9.4 and 0.73 ppm wet weight, respectively. PCBs occurred in 25 eggs with a high value of 3.5 ppm. No other organochlorine compounds occurred in more than 307. of the eggs. Contaminant concentrations were remarkably similar among colonies. DDE was negatively correlated with eggshell thickness (r=-0.48 P < 0.01). Eggshell thickness averaged 4.2% less than for eggs collected before 1947. Contaminants showed no significant link to hatching or fledging success. However, eggs from nests with less than 100 percent hatching success showed a tendency toward higher DDE and PCB concentrations (P= 0.09 and 0.12, respectively).