Radicactivity of common substances and organisms at Er iwe-
tek Atoll was evaluated in two ways, first by concentrated suxy
iavolving many organisms collected frequently at one island,
Belle, and second, by less intensive study at several islands
around the atoll in order to elucidate the geographical distriDBution of the activity.
Belle Island (Fig. 1) vas the
major collecting and observation
inetd tnect
site, except for rats, for which
it was Janet Island.
T .
Callections
| ge
were made on April 15, 1954 at
Gage
foes aaties _—)
Belle before the Nectar test,
muse
almost daily for the week after,
ii
_
and at increasing intervals later.
_
The second aspect of the study,
at severe] islands, involved pre-
Nectar collections in April and
May, and nine to ten post-Nectar
:
collections, usually expedited
by helicopter, at intervals tn-
creasing from one to nine months,
amyl
1 nenaor mwve
at which time six islands. Henry,
Leroy, Alice, Olive, Vera, and
Bruce vere visited.
The remaining two islands, Janet and Elter,
vere sampled at approximately
the same times in connection with
other studies.
cekarey (Opts)
at
"oe
ao
Pig. 1. Map of Enivetok
Atoll
Survey meter readings were taken frequently at Belle, but m
only about half of the visits to other islands.
The Juno meter
was used for high (Table 2) levels of activity and the Geiger
counter (Nuclear, MX-5) for low levels.
‘Several spots
vere
usually monitored with the instrument one inch from the ground
and vith the shield both open and closed.
Similar readings
three feet from the ground vere taken less frequently and are
not included.
Por the distributional study on the various !slands a handful of {sland so!l] from the top iach, tntertidal beach sand «4
few milliliters of sea water, algae. and three se2 cucusters
Were taxen.
Periodic trics ty M-boat around the certphery of the
lagoon, @ mile or two centrally from the islands, served
sampling sea water,
for
plenkton, and velagic fish by rod and reel.
Plankton tows usually lasted from 15 to 3) minutes at frem one to
two knots per hour using two 1/2-meter nets, fine (No.2) of 173
mesh/inch) and coarse (No.6 of 74 mesh/inch) tow stmultane sus ly
from either sije of the M-toat.
‘Large jellyfish
‘f present verremovec and the samples rreserved by adding formalin to maze 56.