The kidney of the Tridacna had the greatest amounts of ®°Co of the marine sam- +) ples analyzed. SUMMARY The DOE's portion of LRE's Pacific Radioecology Program began on 1 July 1974. The purpose of this program is to determine the types and amounts of radionuclides in biological and environmental samples from the Central Pacific, especially the Marshall Islands. in September-October 1976. A field trip was conducted for this program About 340 samples were collected and about 340 y-spectrum, 130 strontium-90 and 75 plutonium-239,240 analyses were performed. Results of the analyses indicate that 99Sr and 13’Cs are predominant in the terrestrial environment and, in addition, 2*!Am and 239°249Py are also important in the soil from Rongelap Atoll. Potassium-40 ts the predominant radionuclide in the marine organisms, while ©°Co is important in the kidney of the Tridacna clams. ‘y Amounts of radioactivity between atolls and and between islands within Rongelap Atoll vary with distance from the test site at Bikini Atoll and in relation to the fallout pattern from the March 1954 Bravo test. Plants from Bikini Island had the highest amounts of radioactivity, primarily 137Cs, while Plants from Naen Island at Rongelap Atoll had slightly lower amounts. The southern islands of Rongelap Atoll and Utirik Atoll had intermediate amounts of radioactivity, while Ailuk and Wotje Atolls had the lowest amounts of radioactivity of the atolls visited during this field trip. REFERENCES CITED Nelson, V. A. 1977. Radiological survey of plants, animals, and soil at Christmas Island and Seven Atolls in the Marshal? Islands. Report NVO-269-32. U.S. ERDA College of Fisheries, University of Washington, Seattle. > . 16