assayed about 10 dis/min Zn®’, 1.3 dis/min Mn™, 4 dis/min Co™ and 0.4 dis/min Co®” per gram
of living organisms.
No new fission products were detected in the lagoon organisms after Shot Cherokeeand Prior
to Shot Zuni.
Figures 5.8 and 5.9 show the typical gammaspectra of an octopus and fish larvae
specimens collected 29 May 1956 from Bikini Lagoon, showing predominately old Zn®, CoS?
Co®and Mn*é,
.
,
~
Following Shot Zuni, 28 May 1956, a number of reef fish were collected on the southern
Bikini reef near Rukoji Channel. Several dead goat fish and trigger fish were also coliecteq
showing visible burns around the dorsal fins. Gamma spectrum analysis one year after the
collection showed Co*’, Co®, Mn*4, and Zn®of the order of 2,500 (dis/min)/gm for the mixed
isotopes in the liver, flesh, and bones of a burned goatfish (Upeneus sp.). Two surgeonfish
(Acanthurus sp.) and a trigger fish (Valistidae) from the same reef showed high concentrations
of Cs", No other specimens of marine life exhibited cesium to such a marked degree. A 175.
gram surgeonfish collected 29 May 1956 assayed 1,200 dis/min Ce!60 dis/min Ru!®, 330
dis/min Cs‘57, 70 dis/min Mn‘, 140 dis/min Zn*®® and 17 dis/min Co®™per wet gram for the en-
tire fish. Considering the high Cs'3’- ce! ratio, it appears unlikely that all of the cesium
could have originated with Zuni. Previous biological specimens have consistently given low or
negative cesium results. Possibly cesium may be concentrated and retained by these fish. A
butterfly-fish (Chaetodontidae) collected at the same time assayed 38 dis/min Co*’, 1,700 dis/min
ce, 200 dis/min Ru!®, 83 dis/min Cs'8", 46 dis/min Mn™, 145 dis/min Zn’, and 7 dis/min
Co” per wet gram of the entire fish as of 1 June 1957 giving the isotope ratios and activity values
roughly the same as in an equal weight of bottom water or in 80 grams of surface water from the
same areas as shown in Table5.5.
Immature cardinal fish collected off site in Bikini Lagoon on 2 June 1956 after Zuni were
contaminated chiefly with 4,000 dis/min Zn®5, 70 dis/min Co™, 17 dis/min Co*! and 75 dis/min
Mn*4 per wet gram at time of collection, producing a gamma energy spectrum similar to Figure
5.9. Although Zuni fission products were detected in the southern central lagoon 2 daysafter
the shot, new fission products were not reflected in fish larvae off site at H+5 days.
At H+ 12
days, myctophids collected by dip-netting had absorbed short-lived (t 1/, = 10 days) complex
fission products of the order of 60,000 8 dis/min per wet gram.
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