longer-term studies indicate that several years after
a single contamination of an area the carnivorous fish
contain the greatest amount of radioactivity.
The carnivorous fish such as tuna and bonito,
caught in the open ocean,
contain zn©®5 at the highest
levels of any of the three groups of fish.
In these
animals Zn©5 accounts for 75 to 92 percent of the total
radioactivity; Fe29-59,
radioisotopes,
6 to 25 percent; the cobalt
1 to 3 percent;
and Mn°4 ,
less than 1
percent.
In all species of fish, the greatest amount of
radioactivity is found in the alimentary tract, with
liver,
skin,
bone and muscle having lesser amounts in
descending order.
Skin and bone are quite similar in
the amounts present,
and usually the radioactivity
averages about twice that found in the muscle.
The
liver may have two to nine times as much radioactivity
as the bone or skin,
and the alimentary tract contains
two to four times as much as the
Liver.
During the spring of 1954 a series of experiments at Bikini
and Eniwetok Atolls produced radiation that really initiated
full-fledged oceanographic studies.
Hines
(1962) describes the
events that led to the radiological evaluations over much of the
western Pacific.
The Operation Castle test series was opened at
Bikini on March 1,
1954.
proving ground was Bravo.
The first detonation in the
Its yield in energy release
was placed at about fifteen megatons.
At such a level