-
24 -
The decay rates of algae from the intertidal zones of eight islands
are givenin Table 8.
In general the decay rates for the different species
collected at one island were the same.
It was found, however, that the
decay rates varied depending on the date of collection.
The radioactivity
in the algae collected at Henry and Leroy Islands decayed faster than tha
inthe algae collected at other islands ( Table 9).
Table 9.
Summary of the decay rates of algae collected on four dates
at Leroy and Henry Islands, and at six other islands combined, expressed as the negative slopes of logarithmic plots.
Date of
collection
Leroy Is.
Henry Is.
Other islands
6/3/54
1.8
1.5
1.3
7/20/54
2.0
— 2.0
1.5
10/54
2.6
2.3
1.3
2/55
2.7
1.7
1.1
From these data it appears that the algae at Leroy and Henry Islands absorbed radionuclides with relatively short half lives.
A similz
conclusion was reached with samples of invertebrates collected at
same time 8)
nation
from
activity at
of the atoll.
the
These observations indicate that the residual contami
previous
detonations
accounted for less of the radio
these islands than it did at the islands in the northern e: