-127- 2 (see Table 7), AECD-~-3446 At Eniwetok there is a conspicuous reduction in .1e amounts ‘*adioactivity at Rigili and Igurin, and a decline of Engebi from the position of s highest in activity of invertebrates in 1948 to third place in 1949. It will be fed also that counts of algae showed the position of Engebi to drop from second 1948 to third in 1949, Perhaps the collections on Engebi in 1949 were not from most active portions of that locality. The section of the present report dealing th the distribution of radioactivity on land shows great variability of intensity : relatively small areas near the target localities. If the same condition may ‘assumed to exist in the water, a slight change in position of the sampling sta-. nfrom one year to the next could effect noticeable change in the radioactivity the invertebrates, At any rate the possibility of more rapid decay of material ga Engebi than from other stations was negated by recounts in June, 1950, of im two to six of the 1948 samples from each of the three Eniwetok blast locali~ No significant difference in the rate of decay over the 1-1/2-year period mong the islands could be observed. - Several points of interest merit discussion, Comparison of the inverte- tes as a whole with algae shows more radioactivity in the algae than in the if jertebrates at the Eniwetok Shot Islands, but not in the Bikini Target Area. 7B ch sessile invertebrates as hydroids and encrusting sponges exceed the algae. ° 948 the algae and invertebrates were about equal in radioactivity at both In 1949 the invertebrates as a whole were less radioactive Be i iF like crabs, clams, snails, and urchins were assayed in the latter year. ver, higher counts were obtained from certain invertebrates such as star: i, hydroids, oysters, and sponges, than from any of the algae sampled. Indeed, e ntrance and path within the organism of the relatively great amounts of - 2 oo. Low levels of radioactivity among the corals, which are sessile, planktong organisms, present an anomaly, the hard, calcareous type. Coral samples were almost exclusively In preparing the samples, hard parts were not separa- from protoplasmic portions, so that unless the hard parts were radioactive, E Bi ie J we UNIVERSITY AT CNIVES TNIV Eg Pe ET TR TIN RD oe CpsegeR ms mage ow, omen TERRE cgMNeIERIE Tene Didi ee a ey Rye CY REE OR ICa Tere be be tly ae MME EE wl DAEted n the algae, probably because relatively more of the low-counting types of ani- / ~™ iand Eniwetok, i