The variability that may be expected from two collections
taken in close proximity is pointed out in the comparison of
two collecting areas on Engebi.
Tide pool collecting at the
west tip on the lagoon side yielded invertebrates containing
significantly less radioactivity than did those collected on
the outer, north shore.
The average of all samples as well
as counts of comparable tissues were alike in this respect.
See Table 1 in the Appendix.
|
The relationship of radicactivity to animal group is not
so clear as
it is to locality.
Comparison with 1949 findings
at Eniwetok shows mutual tendencies toward high activities
in samples of hydroids,
sponges,
starfish,
and oysters,
in
descending order of magnitude, with crustaceans and corals
conta ining relatively little radioactivity.
Table 7 gives frequencies of counts by magnitudes for the
major collecting areas for both pre and post shot material
exclusive of dredged samples.
The trend for high counts to
predominate near shot areas is almost the same both pre and
post test.
Table 7 also serves to demonstrate that the frequency
of distribution of logarithms of counts in the post test series is approximately of the normal form,
whereas the dis-
tribution of the observed counts would be strongly skewed.
In the pre-test series the distribution of the logarithms of
the counts is normal only in the “hotter" areas and then only
if background counts are excluded.
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