45 Gamma spectra were determined on plankton from station 42 and on portions of this sample including the formalin preservative filtrate, the Fe (OH), scavenge from the ashed plankton sample, and the cobalt separation on the same specimen (Fig. 12). The total plankton sample has a lower n°? component than that found in sample 54. 12 144 ru’ 106 -R ho In addition Cet 4 ’*-prt?*, 06 and gr?°-Nb?> contributes little of the total gamma radiation (Fig. 12}. The major part of the gamma activity is contributed 6 59 by Co?! , C028 and Co °, also a limited amount of Fe is present. The cobalt in plankton sample 42 ts partly soluble in neutrel formalin and is found in high amount in the filtrate. eT though some evidence of the Ce 14 4 pita planxton curve on the low MEV range, is gives only the cor! Al- peaks are present in the the curve on the filtrate pesk (Fig 12, inset). This peak is also shown by the cobalt separation from plankton sample 42 tin the pre- same figure. In summary, the g&mma-spectra findings on non-fission prod- ‘yom ucts in both the Walton end Marsh plankton samples are as follows: Station gn 1is- Levels of non-fissionproduct isotopes Zne> Walton 8-C , 11). Marsh te HR Re ti Re n.d. low n.d. n.d. 54 * + low n.d 5 4a * # + n.d. + + FeJ 9-D 55 id + + Cobalt isotopes + +t + + 4 very high high not detected low low + + n.d. n.d. +