19 Table 1. The sums of the values of activity of the residue from one liter of sea weter and of the filtered water, less K exch atation and depth are given in Table 2. 4Q 3 for Figure 4 is a graph- te presentation of the data from Table 1 along with the plankton values. It is evident from this figure that elthough the abso- lute values for the various depths or kinds of samples are differ- ent, the general pattern of horizontal distribution of activity ie approximately the same. The distribution of activity in the surface water samples is plotted in Figure 5. The highest levels of total activity in the surface water (residue on filter paper plus fillterable portion, less Kt) were found tetween Fniwetok and Ujelang, and the lowest value north- east of Bikini. These values were 19,000 d/m/l and 48 d/m/1. Values in the vicinity of Guam are 4 to 20 times the lower value, indicating that some contamination from Operation Redwing had reached this far. Possible interpretations of the relation- ship between water and plankton activity are discussed on pages e7 - 33. At every depth sampled the particulate matter retained on the filter had lower levels of activity than did the filterable fraction; this was true also for the Walton samples with the exception of the surface water, in which the particulate matter The average values of ra- dioactivity in the two fractions and the percentages from both the Marsh and Walton data are presented for comparison in Table 3. In both sets of data the particulate matter contributes et about three times as much of the total activity in the surface at *t contained 58 percent of the activity.