Radiation Effects of Tritiated Seawater on Development of the Goose Barnacle, Pollicipes Polymerus

Barnacle embryos were reared in millipore cytology monitors containing approximate tritiated water (HTO) concentrations of background plus 0, 10−5, 10−4, 10−3, 10−2, 10−1, and 100 microci/ml. After 32 days the cultures were fixed and the numbers of larvae counted. A “molting index,” the percentage of larvae that molted at least once, was used to evaluate the effects of HTO on normal development. Effects were observed at concentrations as low as 7 × 10−6 microci/ml, and were exponentially related to HTO concentration. Factors affecting sensitivity and possible environmental implications are discussed.