Transuranics and Other Radionuclides in Bikini Lagoon: Concentration Data Retrieved from Aged Coral Sections

• Published in: Limnology and oceanography Vol. 20; no. 5; pp. 729 - 742
• Main Authors: Noshkin, V. E., Wong, K. M., Eagle, R. J., Gatrousis, C.
• Format: Journal Article
• Language: English
• Published: American Society of Limnology and Oceanography 01-09-1975
• Subjects: Atolls; Autoradiography; Bikinis; Corals; Lagoons; Oceans; Plutonium; Radionuclides; Sea water; Sediments
• ISSN: 0024-3590; 1939-5590
• DOI: 10.4319/lo.1975.20.5.0729

X-radiography and autoradiography of thin vertical sections were used to estimate the growth rate of a specimen of Favites virens from Bikini Lagoon. Discrete bands of radioactivity were identifiable with specific nuclear test series. The coral growth rate of 8.0 mm year-1 determined by autoradiography is in good agreement with the rate of 8.1 ± 2.2 mm year-1 derived from the "seasonal" alternating light and dark bands on X-radiographs. With these bands as growth rate indicators, the coral was sectioned into yearly increments and analyzed by low-level, nondestructive gamma spectrometry, radiochemical techniques, and mass spectrometry to reconstruct the variations in the concentration of transuranics and other radionuclides in the marine environment at Bikini since 1954. From the concentration data retained in this indicator species, the exchange rate of radionuclides between the lagoon and the open ocean is computed to be longer than exchange rates based on physical circulation data. There is no constant ratio of plutonium isotopes in the coral growth sections, suggesting that the redistributions of the several plutonium isotopes in the environment may be governed by different biogeochemical processes. Increased levels of210Po(210Pb) were found in test-year growth sections, contradicting previous arguments that no 210Pb has resulted from weapons testing.