—, Gamma spectrometry on ashed samples revesled that certain radioisotopes such as Zn®® C057, Co? and Mn®4 were common in all soft tissues examined, while only Zn®8 ang Ma®4 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 sampies from Ailinginae Atoll. These samples exhibited the characteristic gamma spectrum of fish tissues from the three areas. The presence of the radioisotopes mentioned above was verified and quantitative estimates of the radioactivity of each isotope in the sample were made. using mase absorption techniques. In addition Fe55 was found About 40 per cent of the total radioactivity was due to zn85; 38 per cent to C097, C098, and C089; 28 per cent to Fre°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 fleh bone of the Rongelap region but only in very small amounts. |