and Rigili and Runit alternating in position. The activity in the gut had a sequence similar to that of entire fish because the gut and contents were the greatest contributing factors. The greatest increase of radioactivity in posttest fish over preshot levels was in the islands to the west and south of Elugelab, where it was especially noticeable in muscle, skin, bone, and liver. In spite of the fact that Bogallua fish had slightly leas activity in the gut, several times as much activity appears in the liver, bone, skin, and muscle as in postshot fish from Engebi. These data seem to indicate that the metabolized and, to some extent, the adsorbed (onto the skin) radioisotopes were available in greater amounts at Bogallua; i.e., they were carried westward from the target area by currents and wind in the lagoon. This is partially substantiated by the presence of turbid water west and southwestof the target area. It must be noted also that much of the activity at Engebi was preshot and probably made up of considerable inert material, biologically speaking. A large number of dead and dying fish were seen in and close to the turbid water flowing from the target area westward inside the lagoon between Elugelab and Bogallua eight days after the blast. There were some injured fish at Engebi also, and two or three badly injured goatfish were collected near the shore (Fig. 4.3). le 4.5.3 - Analysis by Species and Feeding Habits Amongthose fish which are fairly well represented in the samples, the damselfish appear to ingest the greatest amount of active material, followed by surgeonfish, butterfly fish, parrot fish, gobies, wrasses, squirrelfish, cardinal fish, and groupers. Other species, of which we have only a [ew samples and which indicate their ability to absorb active materials, are filefish, blennies, puffers, and eels (Table 4.11). As the range of disintegrations per minute per gram indicates, there is great variation from species to species, island to island, and even nf: - from specimer to specimen, especially evident in the postshotfish. Omnivorous species almost invariably showed more activity than carnivorous species from the same area, Exceptions were found at Igurin and Japtan (Fig. 4.4), where activity was more or less similar in the two groups. Comparis-ns of preshot activity at other stations indicate that the omnivores are two to seven times ae -adioactive as the carnivores. Comparisons of postshot activity indicate that the greates: uliference existed at Engebi, where omni- - . 7 - f@re mI vores were about 32 times as radioactive as carnivores, and at Aaraanbiru, where omnivores were about 30 times as active. The data indicate that the omnivores to carnivores ratio of radioactivity was greater at Aaraanbiru and Engebi than at Japtan and Igurin. This is further substantiated by comparing like tissues of carnivores and omnivores. At Japtan and Igurin comparatively small amounts of preshot radioactive material were taken into the gut of either omnivores or carnivores, and approximately equal amounts were retained in the muscle, skin, bone, and liver. On the other hand, at preshot and postshot islands, where the activity was comparatively high, the omnivores took in considerably more radioactive material in feeding than the carnivores but retained proportionately less in the liver, bone, skin, and muscle. For example, at Engebi and Aaraanbiru the activity in the gut of omnivores was approximately 21 and 125 times as great, respectively, as in carnivores; yet the radioactive materials retained in the muscie, skin, and bone ranged from only 2.5 to 7.2 times as much in omnivores. It sould be pointed out, however, that, because of the great variation in activity of the gut, both within and between species, any conclusions made should take this factor into consideration. 4.5.4 Analysis by Tissues or Organs The data for the analysis of tissues or organs are summarized in Tables 4.12 and 4.13, in which the wet weight of tissues (disintegrations per minute per gram) is compared by islands and by feeding habits. Part of the material has been discussed on the preceding pages. " -