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DISCUSSION
The algae samples collected one to two days after the nuclear detonation of May 14, 1954, contained the highest amounts of radioactivity
of the samples collected during the survey.
The radioactivity of the
later samples diminished at a rate faster than can be accounted for by
the decay of mixed fission products (t7!- 2) 10)
indicating that factors
other than physical decay were responsible for the diminution of radioactivity in the samples with time after detonation.
One of the factors
involved, undoubtedly, was the loss of radioactivity in the sea water in
which the algae were growing.
The radioactivity of the water was much
lower per unit weight than that of the algae, but the rate of loss of radioactivity was approximately the same, which indicates that the amountof
radioactivity in the algae was dependent upon that in the water.
Since the
water in the vicinity of Belle Island was highly radioactive immediately
after detonation, the mixing of uncontaminated water from the ocean and
less contaminated water from the southern portions of the lagoon would
tend to lower the radioactive content of the water surrounding Belle Island, and,
this water.
consequently, the radioactive content of the algae living in
Thus the radioactivity in the algae would tend to decrease
with time at a rate faster than would be expected by the process of radioactive decay alone.