. The effects of atomic radiation on oceanography and fisheries, report . FiGURE 2. Uptake of Zinc^^ by Nitzschia Cells from Culture Medium Containing 10 Micrograms of Zinc/Liter. centration of zinc in sea water, a dividing cul- ture of Nitzschia depleted the zinc'^'' in a closed system in less than one day. Apparently phyto- plankton cells concentrate zinc relative to sea water and any radioactive zinc present in the water will be quickly taken up in large amounts. The radioisotopes so far discussed are very likely always ionic in sea water. Ruthenium solution, however, forms colloids and par
. The effects of atomic radiation on oceanography and fisheries, report . FiGURE 2. Uptake of Zinc^^ by Nitzschia Cells from Culture Medium Containing 10 Micrograms of Zinc/Liter. centration of zinc in sea water, a dividing cul- ture of Nitzschia depleted the zinc'^'' in a closed system in less than one day. Apparently phyto- plankton cells concentrate zinc relative to sea water and any radioactive zinc present in the water will be quickly taken up in large amounts. The radioisotopes so far discussed are very likely always ionic in sea water. Ruthenium solution, however, forms colloids and particles when put into sea water. Ruthenium^o*^ ob- tained as an acid solution from Oak Ridge was added to a sea water culture of Nitzschia cells. Figure 3 shows that the cells continued to take up the ruthenium for the 12 days of the experi- ment. Tlie amount of ruthenium per cell de- creased, however, since the cells of the culture were dividing continually. One may conclude from this experiment, that since the ruthenium concentration in sea water is low, dividing planktonic algae would take up large amounts of any radioactive ruthenium present. Second trophic level The work reported in this section was also done at the Larvae of the brine shrimp Artemia were put into filtered sea water containing radiostrontium and the daughter 16 / <n / UJ / 1;^ / o £ fel2 / D g M J g < \ f t- £ 3 1 8 t 5 ;^ / o I X / (/I / H Z 3 4 O U / Figure 3. Uptake of Ru^*^ by Nitzschia Cultures in the Light. yttrium^". These larvae rapidly took up the SR*^-Sr^°Y^° and reached an apparent steady- state in a few hours. After exposure of the or- ganisms to the isotopes for one day, it was found that the amount of radioactivity/g of Artemia was only 70 per cent of that of an equal weight of the sea water. A count of the samples 30 days after their preparation indi- cated that a considerable amount of Y°^ was taken up. Other crustaceans used were the shrimp Penaeus setiferus and t
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