-4At Belle Island,
the invertebrates usually sampled were the
killer clam Tridacna, the spider snail Lambis, the land hermit
crab Coenobita,
the black sea cucumber Holothuria atra, and the
branching corals Acropora, Porites, Pocillopora, and Heliopora.
Fish, and aquatic
invertebrates were usually collected along the
north or ocean side, algae on the lagoon and ocean sides, land
plants in the central portion, land hermit crabs among the
bushes of the north edge, and terns nearby. Rats were obtained
centrally on Janet Island.
Invertebrates and fish were collected at low tide when
possible.
Biological specimens were put on ice in insulated
containers and transported to the laboratory at Elmer Island for
immediate preparation or for freezing until time was available
for dissection.
Soil samples were dried and packaged for shipment.
Five-
milliliter samples of sea water were dried on 1 1/@-inch stain-
less steel plates and ashed, except that in 1956, 100-milliliter
samples were used because of the low level of the activity.
These were treated with sodium carbonate to remove potassium
(K+O contributes about 0.6 disintegrations per minute per
milliliter), and then filtered, and the precipitate used for
counting.
Radiocesitum is also lost by treatment with sodium
carbonate (UWFL-46: 10).
Plankton was prepared by filtering and removing as much as
1-2 grams to the 1 1/2-inch counting plates, drying, and ashing.
From occasional poor tows the wet sample weight was as low as
O.1 gram.
Portions usually sampled from the invertebrates were:
from
clams, mantle, adductor muscle, gill, kidney, visceral mass, and
shell;
from spider snails, mantle, muscle of foot, terminal
portions of liver and gut, visceral mass, and shell; from the
land hermit crab, gill, digestive gland or liver, gut, carapace,
and muscle of leg; from sea cucumbers,
gonad when suffictently
plentiful, gut and contents, muscle of the body wall, and body
wall or integument with or without attached muscle; and from
coral the terminal portions of small branches.
Shell samples of
clams and snails were usually taken from the thin edge to include
periostracum.
The term gut as used in this report implies any portion of
the digestive tract not more specifically designated and includes
the contents.
Sample size was influenced somewhat by the nature of the
sample and the amount of radioactivity present.
was low,
larger samples were used.
When activity
Between 50 and 200 milligrams
of ash were usually considered desirable, but weights ranged
widely, from less than 10 to more than 1000 milligrams.
Shell
and gut with sandy content were more lightly sampled on 2 wet
pu
ck
y AR
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