-
19
-
the maximum permissible level for foods.
activity in tuna fish was 3.5 d/min/g ash,
The highest
less than
1 percent of the permissible level.
4.
Measurements of plankton activity offer a
sensitive indication of activity in the ocean.
5.
Similar operations would be valuable in assessing
the activity from future tests and in gathering valuable
data for oceanographic studies.
In the planning for the 1956 series of tests at Bikini and
Eniwetok (Operation Redwing)
it was decided to carry on oceano-
graphic cruises during and following the tests to determine, if
possible,
the
were planned,
levels of ocean-borne contamination.
Two cruises
one during the test period to outline the area of
contamination,and a second after the completion of the tests to
determine the spread over the ocean of contaminated water and
to trace the farthest drift of the fallout after it had been
dispersed and diluted in the ocean.
A destroyer escort,
survey ship.
the U.S.S.
Walton,
was used as the
first
The cruise plan covered an area 400 miles in length
and 200 miles in width.
Samples of sea water and plankton were
collected from fifty-three stations over a 78,000 square-mile
area.
Hines
(1962)
summarizes the
survey results.
Analysis of the Walton's samples disclosed that
radioactive contamination was present in relatively
heavy concentrations in identifiable locations within