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Sea Water
A total of 79 sea water samples were collected and analyzed.
The data are given in Appendix Table 3 and summarized
in Table 8.
As in the samples of fish tissues and plankton,
the levels
of radioactivity were low and the 95 per cent counting error was
often very high.
In more thantwo-thirds of the counts of the
water samples that were significantly greater than the background count,
the. 95 per cent counting error was more than 50
per cent of the value of the count.
In addition, two-thirds
of the radionuclides sampled showed no detectable levels of
radioactivity (see Appendix Table 3).
The radionuclides ruthenium-103,
zirconium-niobium-95,
and cerium-141,144 were present in highest amounts and occurred
most frequently in the sea water samples.
A few samples con-
tained barely detectable amounts of zinc-65, cesium-137, and
cobalt-60.
The strontium-90 levels in five water samples ana-
lyzed were also very low,
ranging from 0.034 pc/l to 0.193 pe/l.
The data in Table 8 indicate also that in the mixed layer
above the thermocline the radioactivity was less at the surface
than in the layers immediately above and below the thermocline.
Potassium Analyses
More than 600 samples of fish tissue,
plankton,
nekton,