Mean 40% concentration
TOL

2oO
O

—

5 7

|

.

A 137, - entire fish
B

3

v

1.0bR

©
2

0.5-

c

0.3

——

i= eviscerated whole fis

E

207, ;

e

a

h

|

fi

a

h

7

2

a

ec

=

o

2

7:

= viscera

7

6

“oO

155 Eu

D 207, - viscera

5

£

-

IS5ey - eviscerated whole fish

Cc

2
~

J

Column legend

=a

bs
OF FIL

7

hr

r

ry

m7

I

pa
|

a

ry

ba

z

© 0.05g

jd

=~ 0.03 -

hs

=

=

4
{

0.0) LUAIBICHOLE] TARsichodel tafetctcte)Ags tcpfeh Pap atcfope) AgegCJOFE] AB POVEY Av etcporey
BELLE

RENE

JANET

URSULA YVONNE

DAVID

FRED

HENRY

PAL FIFE
LERCY

Collection site
Fig. 160,

Average 13Tog

levels (av 15 pCi/g).

and 207; concentration in convict surgeon from

but 25 pe,

1972.

The 40k value is the mean for

9

No 69 Go, 207 Bi,

or 155.) were observed,
9055,

155

Enewetak Atoll, October to December,
all convict surgeon samples,

800 and 2075; data for the two collection

137 a5

and 239, 240 by were found in some

periods,

The effective half-life of 2.7 yr

for 8005 {radioactive decay half-life

or all of the samples, usually at levels

5.24 yr) and 5.1 yr for 207 Bi {radioactive

comparable to the lower values found at

decay half-life 30 yr) implies an effective

Enewetak.

half-life in the ecosystem for both isotopes

As. with the plankton,

comparison of

of about 5-6 yr.

data obtained from this survey with similar

Of the marine invertebrates present at

data from samples taken in 1964 indicates

Enewetak, tridacna clams, Sea cucum-

that, for some nuclides at least, there are

bers, spiny lobster, and top snails were

processes operating to reduce concentra-

collected and analyzed,

tions in the lagoon faster than is expected

806 was the most abundant radioisotope

from radioactive decay alone,

found, and it was present in higher

Table 220,

In the tridacna,

amounts in the kidney than in the viscera,

for example, presents a comparison of
I-24

Select target paragraph3