34
short-lived radioactive anions such as Np? 39, Mo?9-7079,
tet32_7132,
Fe?>,
after six weeks,
the induced
Fe2? and Co? /.58-60 predominated.
and
radioisotopes zn®5 ,
Reviewing the results
of four surveys of radioactivity in the sea near the Eniwetok
test site conducted during the period 1956-1958,
Lowman (1960)
stated that only a small fraction of the total radioactivity
in the sea was associated with the plankton.
The average
total radioactivity in the water was 40,000 times that contained in the plankton.
However,
the radioactivity per unit
volume of plankton was much higher than for an equal volume
of water.
Lowman,
Palumbo and South (1957) gave the pattern of
distribution of the induced radioisotopes of the transition
elements manganese,
Proving Ground.
iron,
cobalt and zinc at the Pacific
In general,
they were found to be present
in the sea and not on the land,
marine plants.
in marine animals and not in
Few or none were present in the island soil,
in land plants or herbivorous field rats.
plankton,
However,
in the
marine invertebrate filter feeders and omnivores,
and in fishes,
these radioelements were present and contribu-
ted up to 100 per cent of the total radioactivity.
The radioactivity in the reef fishes of Belle Island in
Eniwetok Atoll was reported by Welander
(1957)
to decline more