-Go=—
The birds, which feed almost exclusively on marine organisms,
contain primarily zn®> and occasionally small amounts of
Mn>4 and co®9,
gsr99 is also found in small amounts in bird
bone and may reflect direct uptake from the ingestion of soil,
although there is no direct evidence that this occurs.
Radionuclides in fish are limited to mn>4,
the latter being predominant.
CoS ana zn®5 ,
On a dry-weight basis for a
sample of goatfish testes have the highest levels,
the liver,
gastro-intestinal tract and eyes are lower by about an order
of magnitude,
and the muscle and bone lower by still another
order of magnitude.
If the total amount of radioactivity by
tissue is considered then bone is the principal depository of
an 65
gn°>
(Joyner,
1961,
personal communication).
for fish are open to question.
The sources of
In some instances inverte-
brates containing zgn®°5 are known to be consumed by fish found
to contain zn©5 ,
but,
in general,
no definite sources of Zn
are known to exist five years after fallout.
It is possible
that there is concentration of undetectable levels from the sea
water or algae.
The possibility that most of the zn©> activity
in fish is residual appears to be ruled out by the fact that
young fish contain relatively high levels.
The marine invertebrates
taken as a whole contain a wider
spectrum of radionuclides than do the fish.
These are Mn>4,