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Bikini-Eniwetok test site has provided a variety of radio{isotopes that become biological tracers for field experiments in mineral metabolism,

valuable information has been

acquired on the distribution of many elements in the marine
biota.

However,

to understand the transfer processes and

the piological effects of radiation, experiments under
controlled laboratory conditions are required.

Conversely,

results of laboratory experiments that are to be extrapolated to the natural environment require field testing.
Many of the observations by the staffs of the

Laboratory of Radiation Biology,

University of Washington,

Seripps Institution of Oceanography,

and the Naval Radio-

logical Defense Laboratory on the uptake of radioisotopes
by marine organisms in the natural environment have been

verified and supplemented by the laboratory experiments of
the Radiobiological Investigations of the Bureau of
Commercial Fisheries and the Hawaii Marine Laborator,

University of Hawaii.

For example, Lowman (1956) and

Schaefer (1958) have reported from field observations and
Chipman (1959) from laboratory experiments that zooplankton
rapidly accumulate radioactive particles.

Chipman states

that when the radioactive particles are no longer available,
the zooplankton soon lose their radioactivity.

Oysters,

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