‘ A et 13 Six species of fish were collected from three sites in the lagoon at Rongelap Atoll. Naturally occurring K was the predominant radionuclide detected. Concentrations of 40kBeer? 955 10 pci/g. Values of the three fallout radionuclides measured, 37Cs, and 20Sr were less than 1 pCi/g, except for the viscera of mullet which had 90sr levels of 1.1 and 2.7 pCi/g. Tridacna clams from the lagoon off Rongelap and Kabelle Islands contained 60Co as the only significant fallout radionuclide. Cobalt-60 levels were highest (11 pCi/g) in the kidney and low in the mantle and muscle. Potassium-40 in the tissues of these clams averaged 7.841.4 pCi/g. goants rotorRongelap contained 137e5 and 2995p in greater quantities than 4 1 5he cgncentration in Pandanus leaves was 4.4+1.8 pCi/g while the 137¢5 ed Osr concentrations were 33419 and 30117 pCi/g (dry), respectively. ants from ke northern istands of Lukuen and Lomuilal had higher levels of 8 Osr and 13/cs than did similar plants from Rongelap Island in the southern part of the atoll. Soil samples were collected from six islands inp Rongelap ftolt. gamma-emitting radionuclides, 60co, 125sb, 137cs, measured in most samples. 155Eu and Five “41am, were Strontium-90 and 239, 1p, were also easily measured in the samples analyzed for these radionuclides. Cesium-137 and Sr were the most abundant offghe above radionuclides as shown in Figure 4. Americum-241, 239:240py, and 15°€u were the next most abundant radionuclides. phey were ggnmonly present in concentrations between 10 and 50 pCi/g while Oco and } aa values were less than 10 pCi/g. At Rongelap Atoll, soil from the northern islands of Lomuilal, Lukuen and Gejen had the highest radionuclide values of the six istands sampled. The amounts of radionuclides in soil from Rongelap Island were about a factor of ten Tower than amounts in soil from the northern islands. Bikini Atoll] Samples were collected at Bikini Atoll? in April and December 1974 and in April 1975 for analysis in our Laboratory. One coconut crab, Tridacna clams, nine species of fish, plants, and extensive soil profiles werg ptaken for gammaspectrum analysis. Selected samples were analyzed for °”Fe, 90Ssr, or Pu. Results of these analyses are shown in Appendix Table 6 (coconut Crabs), 14 (Tridacna clams), 22 and 23 (fish), 24 and 25 (plants), and 26 through 37 (soil) 1. Animals and plants A single coconut crab captured on Bikini Island by an inhabitant of the jgland was ghurchased by us in 1974. In the muscle from this large crab the 7¢s and 90Sr values were 380 and 16 pCi/g of dry weight, respectively. Sixteen hundred pCi of 7¥Sr per gram were found in the exoskeleton of this crab. Plutonium-239, 240 concentrations in the three tissues analyzed were about 0.02 pCi/g. Few coconut crabs remain on Bikini Island due to the destruction of the native vegetation during the rehabilitation of the island. Tridacna clams from the lagoon near Bikini Island contained 60co in kidney tissue in amounts up to 322 pCi/g of dry weight. Cobalt-60 concen- trations in the other tissues from this clan were "gs 3 bp an 20 pCi/g. Values for other fallout radionuclides including &Bsr and 4Upu were less than "DOE ARCHIVES