water, or radionuclides may be adsorbed on the surface of the
animal.
Although adsorption is an important means of contami-
nation of organisms by fresh fallout, it is probably no longer
important at Bikini, where the last significant fallout occurred
in 1958.
The astronomically large surface area presented by the
masses of branching corals and their associated flora and fauna
must have removed,
from the water,
all adsorbable radionuclides
not already removed by the plankton soon after fallout.
The land organisms contain primarily the long-lived fission
products 13765 and 905, and, as expected, these radionuclides
are found associated with those tissues or organs which contain
potassium and calcium, respectively, since cesium and potassium
behave simiiarly in metabolism, as do strontium and calcium.
There are quantitative and qualitative differences in
radionuclide content of organisms associated with feeding habit.
The goatfish,
a bottom-feeding carnivore,
and 20755 than the convict surgeonfish,
or the mullet,
carnivores,
hGandoas
207
Bi
a plankton feeder
the grouper and ulua,
(Table 4)
contains more 6000
a grazing herbivore,
(Tables 2 and 3).
also contain more
Higher order
600, and
than the convict surgeonfish; however,
the
differences may be associated with age as well as with feeding
of Eneray
Denartment
habit.
Historian’s
Office
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The smaller, and presumably younger, reef fish of a species
contain less 90 Sr than the larger fish of the same species