~ 43 ~
pared with that of northern Rongelap.
The fish utilized for food by the
terns are small (one to two inches in length) and travel in schools in the
open waters of the lagoon.
A satisfactory method of obtaining samples of
these animals has not been found, other than that of taking them from the
gastrointestinal tract of the birds.
Tern eggs were collected in October 1955 at Labaredj and Kabelle Islands.
Previous collections had been made at Kabelle on July 16, Decem-
ber 8, 1954, and January 29, 1955 5.
The levels of radioactivity in both
the shells and yolks of eggs of the last collection were low, approximat-
ing those found in the bones of terns from the same area.
In contrast to
the logarithmic decline and decay curves observed for tern bones, radioactivity in the egg shells declin&semilogarithmically with an 80-day halflife; the decay curves also exhibit semilogarithmic decrease with time
but contain two.components, one with a 50-day half life and the other with
a 300-day half life.
The rate and type of decline for the egg yolks cannot be determined
because of the great variability in the average values for the various
collecting dates.
Plankton
The equipment and methods for obtaining the October 1955 plankton
Samples were the same as for the previous Rongelap collections, except
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a
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