Tuna Fisning
goes westward at about 15 to 18 nautical miles ver day.
On approaching the
Philippines this current sweeps northward and most of it @mters the region
to the east of Formosa. However, these currents are not well defined during
this season of the year and on approaching Janan are confused and variable.
South of the Marshalls, there is a counter current setting to the east which,
shifts with the season, mut may reach a velocity of 15 miles per day. This
current never seems to get as far north as the northern islands of the Marshalis.
Access to the southern tuna fishing areas in the region of the Solomons, Samoa
and Gilbert Islands would not seem to be appreciably interfered with by the
present danger area save in the case of the “ilbert Islands.
Contamination of Fish. Tuna fish have been cavght in the northern Marshalls
Following the first detonation but results are not yet available. Fish caught
after the MIKE shot of IVY 2-1/2 to 3-1/2 miles from the crater 6 days after
the shot gave the following results:
1.
2.
Activity in whole fish (average)
25 po/gram
Activity in Tissues(vet Weights)
{a) Muscle = I76 jic/gram wet tissue
(pe - microcurie)
(>) Liver ~ Dyc/pram
7
(c) Gut ~ 34 ne/gram
From considerations of current, the depth of mixing of surface water, the
rate of decay of fission products and the decree to which fish in contaminated
water tend to absorb fission products, I reached the conclusion that the
probalility of significant contamination of fish outside the immediate test
area is inconsequential and that in all likelihood we will be unable to
detect these waters more than a few hundred miles away from the Marshall
Islands, The attempt, of course, will be made to measure this contamination.
John Cc.
Director
pugher,
Hele
Division of Slology and hedicine