Table 1. Potassium and cesium- 137 in Birgus latro latro (coconut crab) muscle collected at Rongelap Atoll and ‘Utirik Island, Utirik Atoll. Kabelle Island Sample no. March i958 (dry season) 34 35 36 CeS5ium-137 Potassium dry weight dry weight d/m/g 604 426 349 37 410 38 (wet season) ‘dry season) 17. 68 /gK Wet/dry ratio 20489 18994 13789 4.212 3.794 3.591 10447 4.082 13. 04 Av. = 13.14 S.D.= 2.81 15092 Av.= 15682 S5.D= 3966 3.743 Av. = 3.884 §.D.=0. 252 7 8 9 661 438 454 17.25 14. 68 11.99 17258 13440 17056 4.930 3.480 3.807 11 12 650 324 475 150 11.92 13.87 Av. = 14.12 S.D.= 2.02 24564 10519 Av.= 1543G S8.D= 5474 3.946 3.660 Av, = 4,022 §.D.=0. 424 924 619 12. 72 12. 64 18546 22065 4.470 4.330 12.00 — 24217 10 325 Av. S.D.= March 1959 13. 28 10. 32 11. 40 uc Cs 137 437 445 95 Av.= 5.D.= August 1958 mg/g Cesium Unit i 2 3 5 731 Av.= S.D= 645 630 85 15.03 11.76 9741 4.308 27993 4,840 5. 140 Av.= 12.28 Av.=23205 Av. = 4.695 S.D= 0.47 S.D* 3956 $.D.=0.366 | yet wet he pack Rongelap Island March 1958 (dry season) 84 85 86 199 219 276 . 87 202 38 Av.= S.D= 261 231 35 12.18 15. 40 19. 20 2,96 14.72 Av.= 12. 89 5.D= 6,09 7356 6403 6474 3.895 4.243 4.419 7989 Av.=11793 5.D+10614 5.130 Av.= 4.276 S$.D= 0.556 30743 3.693