i
7
~<aSh ia a
in Table 5, show that the ratio varied with the species of algae and
ilove:
rin the
with the location of the collection site in the atoll.
In general
the
ce
ee
so
ratio was highest for the fleshy algae such as Lyngbya and Polysiphonia
oar
age Belg etic ie ys a ni titelylang
allow water
- 21-
and lowest for the coralline alga,
The highest ratios or
concentration factors (80 to 86) were obtained from the samples collected shortly after the detonation in the southern portion of the atoll
(Fig.
1).
than unity,
28
30
Halimeda.
Approximately one half of the samples
had ratios greater
indicating a concentration of radioactivity by these algae.
Comparison of Radioactive Decay Rates
The radioactive decay rates of four genera of algae collected at
0.24
Belle Island on different dates were determined and compared with
0.21
each other and with the decay rates of water samples obtained from the
same areas in order to determine whether there were any differences
1.2
in the radioisotopic content of the samples.
he lagoon
genera,
ent water.
with time after the test of May 14,
tly related
‘Table 7).
atio
for the | ;
amount
*
amount
the algae
esults, given
For algae of the following
Halimeda, Caulerpa, and Spyridia, the decay rates decreased
1954,from a slope of -1.3 to -1.0
For Udotea, a semi-calcareous alga, the slopes fluctuated
between -0.8 and -1.5.
In July and November, 1954, at least,
it
appears as though Udotea contained radionuclide mixtures different from
those taken up by the other algae.
The decay of algae collected in May and June, 1954, was slower
than the decay of water samples collected during the same period of time
2 ey yer tf
pot
eng
AR
iN