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17-
concerning the variability in three collections of H. stuposa,
each in-
volving ten portions of the same plant.
Deep waters of the lagoon.
A summary of the results of the radio-
activity of nine deep-water collections of bottom sand and fourteen deepwater collections
of algae is given in Table 5.
The values of
radioactivity for the bottom sand are expressed in uc/kg of dry weight
because they are more reliable than those based on wet weight.
Conse-
quently, when the radioactivity of the coral sand and algae were compared,
conversion factors were
applied to the values for the algae to convert
them to a dry weight basis.
The conversion factors are given in Table 5.
The results show that in the southern end of the lagoon (Rex Island)
the radioactivity of the algae and bottom sand was high
in June 1954,
but much lower (in the algae) in August and September, 1954,
Island) and in March 1955 (Elmer, Glenn, and Leroy Islands).
(Elmer
In the
northern end of the atoll, however, the levels of radioactivity in the algae
and sand were high in March 1955, especially in the vicinity of the detonation (Edna Island).
In the lagoon off Janet and Vera Islands the radio-
activity of the bottom sand was also high at this time.
A comparison of the radioactivities of the deep-water algae and the
shallow-water algae is given in Table 6.
In three of the four cases where
comparisons can be made, the deep-water algae contained higher levels
of radioactivity than did the shallow-water algae.
Further study would be
necessary to determine the consistency of this relationship and to develop