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7, Summary and Conclusions
Rongelap Atoll was accidentally contaminated by radio-
active fallout from a thermonuclear test conducted at Bikini
Atoll in 1954.
ing the effects,
A unique opportunity was provided for studyupon the ecological systems of the atoll,
of
the introduction of artificial radioisotopes whose stable
counterparts are present in only trace amounts in living systems.
Radiometric data from early radiobiological surveys, and
ratios of zinc-65 to stable zinc in fish sampled at Rongelap
Atoll in 1959 were studied.
Inferences were made concerning the
physical state of zinc-65 in the lagoon, and its availability
and specificity for the biological components of that environment.
The significant factors obtained from study of the data
presented are:
(1) Carnivorous fish exhibited consistently higher levels
Of radioactivity due to zinc-65 than omnivorous or herbivorous
fish.
(2) Goatfish, carnivorous fish which feed on the benthos,
generally exhibited higher levels of zinc-65 than other carnivores which feed above the bottom,
and proved to be the most
suitable specimens for comparison of zinc-65 levels between
tissues and between areas.
CE