A resurvey of Bikini, the first of many, was conducted with heavy
radioenvironmental emphasis in July 1947, a year after the Crossroads
tests. The scientific expedition was supported by 2 vessels and included
70 scientists and several hundred Navy personnel.
[Illustration: _Bikini Beach as it appeared in the years after Operation
Crossroads._]
The resurvey group, entering an oceanic environment that had been
completely undisturbed for nearly a year, established at once that
traces of residual radioactivity still were cycling in Bikini’s
ecosystem. For 6 weeks the scientists probed every realm of the atoll
environment, sampling biota, making inventories of plant and animal
communities, and obtaining core samples from the lagoon floor. When the
data had been assembled and reviewed and the reports filed, months
later, there was consensus that Bikini had produced no evidence that
radioactivity, as a separate and identifiable factor, was having any
immediate effect on the health of the atoll, and probably no cumulative
effect, either.
There were, of course, unknowns. So long as radioactivity remained in
the biological cycles there were possibilities of future developments.
In 1947 no other place on earth offered an opportunity to observe the
natural processes by which radiation contamination is eliminated from an
environment. It therefore seemed prudent to compile a longer record,
consisting of other, purely radiobiological surveys at Bikini.
By 1947 the new U. S. Atomic Energy Commission had taken over from the
wartime Manhattan Engineering District the management of the national
effort in the field of atomic energy. A primary responsibility of the
AEC in that period was to press ahead with nuclear weapons development,
but the agency also had specific obligations and interests in the fields
of biology and medicine. Meantime, the testing of nuclear weapons had
been started at a new proving ground at Eniwetok Atoll, 190 nautical
miles west of Bikini.
[Illustration: _Islands on the rim of Eniwetok Atoll, as they appear
today. The marks of man, such as a landing strip, are visible, but
regrowth of vegetation is apparent. Note extent of the reef on both
sides of islands._]