-1]4-
general pattern is that noted above.
This species of rats is essentially herbivorous; they obtain their
food from the land plants, seeking out and eating the seeds of grasses,
sedges, sand burrs, and leaves of some of the succulent plants.
The plants upon which the rats feed concentrate 5r90 and Cs!37,
These radioisotopes account for approximately
radioactivity within
the organs of these
100 percent of the
animals except immediately
after shot,when additional short lived radioisotopes are also present.
During this time, 1!33, 1131 may be present in very high levels in the
thyroids.
By following the pattern of gross radioactivity it has been possible
to
delineate
the broad
trends
in the
distribution of
materials in an atoll and its surrounding area.
radioactive
There. remains much
that can profitably be done to amplify this study, but enough is now
known to point the need for increased
the distribution of specific isotopes.
attention to the task of following
Thus,
more
can be learned about
selective absorption of elements by different organisms, and an unparalleled opportunity is presented to
study
the role of trace elements
in the marine environment.
In the remote atolls of the Marshall Islands important contributions
to biology have been made; the need now is to apply the mowledge,
techniques and skills to increasing the productive capacity of our freshwater areas.
There is every evidence that the rewards in increased