ORGANOCHLORINE CONTAMINANTS IN DOUBLE-CRESTED CORMORANTS FROM GREEN-BAY, WISCONSIN .2. EFFECTS OF AN EXTRACT DERIVED FROM CORMORANT EGGS ONTHE CHICKEN-EMBRYO

White Leghorn chicken (Gallus domesticus) eggs were injected prior to incubation with one of four concentrations (0.001, 0.01, 0.1, and 1.0 egg-equivalent) of an extract derived from 1,000 double-crested cormor ant (Phalacrocorax auritus) eggs collected at Spider Island adjacent t o Green Bay in Lake Michigan. One egg-equivalent corresponded to the c oncentration of contaminants present in an average cormorant egg, This was approximately 322 pg toxic equivalents (TEQs)/g, ww egg with poly chlorinatedbiphenyl congener 126 (3,3',4,4',5-pentachlorobiphenyl) acc ounting for over 70% of the TEQs. Injection of 1.0 egg-equivalent resu lted in 77% mortality at hatch. The incidence of developmental abnorma lities (structural defects or edema) was not affected by injection of the extract. Body weight gain of chicks was reduced in the 1.0 egg equ ivalent dose group in the first, second, and third week's post-hatch. Relative brain weights were greater and relative bursa weights were le ss in the 1.0 egg-equivalent dose group than in the vehicle control at three weeks of age. There were no significant differences in the rela tive weights of the heart, liver, spleen, testes, or comb among treate d and control birds.