For some of the fish the total activity of individuals was
determined, not by randomly selecting by tissues, but by
using weighted samples of all tissues.
group
The activity of the
(fish) was then determined by averaging the values for
the individuals.
Although the two methods for determining
the group average differ in the degree of refinement of the
data, one viewpoint is that the method used for the pre-shot
invertebrates adequately describes the trends and that for
these organisms further refinement is not warranted because of
the nature of the errors in the data.
(3)
Variance of sample counts.
Variance both within
groups and between groups was often great.
The greatest var-
jance and also the highest specific activity were found in th
those tissues with radioactivity from “surface” contamination,
e.g., algae in the digestive tract of fish,
sand in the gut
content of the sea cucumber, algae growing on the carapace of
the crab, or fallout particles on the surface of land plants.
On the other hand the radioactivity of tissues with absorbed
isotopes only,
such as muscle, bone and liver, was less varusually
fable and was/lower.
Consequently,
it is believed that the
greatest cause of variance in the sample counts was due to
the amount and type of food in the digestive tract and/or the
materials on external surfaces.
(4)
Number of items in a sample.
Small samples resulted
from breaking down the collection into small groups such as
Species.
The combination of a few samples and a large value
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OR he HIVES