-16-
samples from Wotho, Tarawa,
Ponape,
and Kapingamarangi, x49
contributed the major portion of the radioactivity.
samples
collected at the
same time
Other
contained wi8l,185_
radioisotopes identified with the 1958 fallout.
Some samples,
such aS coconut crab abdomen and whole fish from Wotho, contained gn®°> ,
none.
whereas others,
such as land plants,
Some of the land plants
contained
contained measurable amounts
of the long-lived fission products e337 and sr?°,
est level of sr?? was
pace from Wotho
isotope by the
The high~
found in a sample of coconut crab cara-
(18 yyc/g dry).
The concentration of this
carapace of land
crabs at Eniwetok has been
reported by Held (1957).
The relatively rapid decay of beta radioactivity in
some of the samples collected in 1956 at Tarawa,
Wotho
(Fig. 2 A-E)
isotopes.
Ponape and
indicates the presence of short-lived
A gamma spectrum analysis of one of the samples
(leaves and stems of a Messerschmidia plant from Wotho)
showed that zr?°-Nb?>
-Nb
this sample.
were the predominant radioisotopes in
Thomas et al.
(1958) found that these isotopes
contributed approximately 684 per cent of the total radioactivity in a duplicate sample.
The presence of short-lived
isotopes in the 1956 samples indicated recent fallout at
these islands.