Results
Gross Beta Radioactivity
Table 1 shows gross levels of beta radioactivity in the fishes during
July 1957.
Of the three islands visited the highest levels were found in
the fish liver tissue from Kabelle Island.
In all cases, for comparable
tissues, the least radioactivity was found in fish collected near Rongelap
Island.
Radioactivity in muscle tissue of fish from Enibuk Island,
Ailinginae Atoll, was as great or greater than that of Kabelle Island.
Comparatively minor differences are seen in the levels of radioactivity in similar tissues of omnivorousand carnivorous fishes from
Rongelap Island, except for stomach contents.
The presence of algae
in the stomachs of many omnivorous fish would account for the higher
levels in these fishes.
Two species, the goatfish and the halfbeak, were taken in sufficient
quantities for separate analyses.
The goatfish feeds on small inverte-
brates, principally crustacea, of the sandy bottom areas.
Levels of
radioactivity in the stomach contents and liver of these fish were much
higher than in other fish of the same area; however, radioactivity in
muscle tissue was not much higher.
The halfbeaks from Kabelle Island
had about the same amountof radioactivity as fish from Rongelap, reflecting, perhaps, a different feeding habit than that of other fish of Kabelle
Island.
The halfbeak normally feeds at the surface on macroplankton,
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