Further, the averige level of activity in plankton from ALlinzinac Lagoon in October 1955 was noted (UWFL+43:44) to be highur than in Rongelap Lagoon on the wet weignt basis. But if the radioactivity per unit of ash weight instead of wet weight is used, tne Ailinginae levels are no higher than in Rengelap Lagoon neer Kibelle Isiani (Table 1). Thus, it seems desirable to repor®t radioactivity of plankton on an ash weight basis, even thouch other organisms and substances migat more desirably be considered on a wet weight basis. Figure @ shows the trend of radioactivity in the plankton samples from Ronselip Javoon (from 1954 through 1958) related to time, USiniy 2 -O7-.c03 niot of che beta activity on an ash weight basis as determined with 2 methane Plow counter. Tables 1 and 2. Data are from ‘The dovted line siowing a decline slope of -3.5 was fitted by inspection to tne minimal points near 300, 600 and 1POo dex:s, points removed as fur as possible from the effects of the Reuwlns and Hardtuck serles of detonations. The maximum level of the lagocn piankton a day or two after March 1, 1°54 may be conjectured by extrapolating back one cycle on Firure ©. It is evident that maxima must have been at least 2),90°5 uc/ks of ash. Furtner reference to Figure ° shows that Bravo must have contributed 10 LOL comes as istic times as mucn activity as Redwing, and Redwing 20 to uch as Hardtack. in tts pattern. The decline picture is character- Rises result from the fallouts, Steen declines until the next fallout. followed by An SeoOe : d ~ anal eee , .