72
than similar tissues from fish caught at Rongelap.
This rein-
forces the inference from the 1957 data that, by the time of
these collections,
there had not been sufficient mixing of the
gamma-emitting radionuclides in the waters of the lagoon to
eliminate the initial differences in the levels of radioactivity between the two areas.
In general,
the data indicate that the distribution of
transition element radioisotopes in a lagoon environment is
controlled by the biota to a considerable extent.
The numbers,
types and ecological relationships of the organisms of the
lagoon therefore,
must have a considerable effect on the dis-
tribution of these elements in the environment.
6.2
Rongelap Survey,
September,
1959
In collecting fish samples during the September
Rongelap Survey,
1959,
particular emphasis was placed on obtaining
samples which would be useful in clarifying and checking the
general trends suggested by the 1957 and 1958 samples.
were made to obtain goatfish
(Mulloidichthys samoensis, benthic
carnivores of the family Mullidae) which,
@arlier surveys,
Efforts
from the data of
appeared to be the best and most consistent
concentrators of gamma emitting radioisotopes among the lagoon
fishes,
and convict surgeon fish
(Acanthurus triostegus,
family
Acanthuridae) which are probably the most purely herbivorous of