spiny lobsters collected in 1969 (Fig. 2). Although the identity of 108m,« has not been confirmed by chemical separation, there is little doubt of its presence because the spiny lobster hepatopancreas is known to concentrate 260-day 110m, (Seymour, 1963). Thus, 108m,5 is another potentially useful long-lived tracer with its indicator organism. Tritium in well water is present at low concentrations; the maximum value found was 14 pCi/ml, or 4300 tritium units, at Nam I.,whereas at Bikini and Enyu Islands the concentration was 2 pci/ml, or approximately 600 T.U. (Table 15). These values fall within the range of tritium concentrations in surface waters of the United States in 1966 reported by Moghissi and Porter (1968). Koranda (1965) has shown that there is approximately 104 times more tritium in bound water than in loose water in soils at. Eniwetok Atoll, but that there is little exchange of the bound water with the loose water. Hence it is probable that there will be no major changes in the tritium concentration of well water at Bikini Atoll. ‘Bikini can be expected to remain a useful area for the study of the redistribution of radionuclides for at decades. least several This is especially true since rapid advances are being Qenartment of Energy ion. made in the technology of radionuclide detect Uistorian’s Office ARCHIVES The present levels of radionuclides and their distribution at Bikini are not likely to change significantly except for a S002Nb2