-24- Gamma spectrometry on ashed samples revealed that certain radioisotopes such as zn85_ Coo? Co80 and Mn°4 were commonin all soft tissues examined, while only zn85 and Mn54 were found in the bone. The similarities between these gamma spectra and those obtained from fish tissues of other areas of the Pacific are pointed out. Chemical separations by ion-exchange resin column techniques were made on fish liver samples from Ailinginae Atoll. These samples exhibited the characteristic gamma spectrum offish tissues from the three areas. The presence of the radicisotopes mentioned above was verified and quantitative estimates of the radioactivity of each isotope in the sample were made. using mass absorption techniques. In addition Fe°5 waa found About 40 per cent of the total radioactivity wag due to zn85. 28 per cent to Coo? C058 and C080, 26 per cent to Fe°5, and about 6 per cent to unidentified radioisotopes. Ion-exchange resin column methods failed to reveal the presence of radiostrontium in the liver of Enibuk reef fish. This radioisotope has been reported occasionally in fish bone of the Rongelap region but only in very small amounts. DEF AR dibeien