Radiochemical Analysis, Radiochemical analysis of the pre-test sample from the Lake George area (Section 4.8) showed that Colds | with 4 half life of 280 days, contributed 74 percent of the radioactivity. Results of radiochemical analyses of post test samples of sand dredged offfRojoa Island and of 3 algae collected in the lagoon 200 yards off Bogallua Island are given in Table 18. From 85 to 96 percent of the total activity of the algal samples is accounted for by the presence of the highly insoluble fission products - cerium, ruthenium, zirconium, and the trivalent rare earths. Since the algae are not likely to take up these insoluble materials in their normal physiological processes, tt seems very probable that most of the activity is present on the surface of the algae, rather than in the cells themselves. This does not, however, rule out the presence of some radioactive salts in the cell structure or in the cell sap. It has been shown that sr? 15 absorbed by plants (UCLA- 247)* and it is generally known that calcium is an essential element in plant metabolism. Thus it its highly probable that & portion of the calcium-strontium fraction found in the analyses is in the protoplasm of the algae. 4.4 Invertebrates In this section the pre and the post test sampling are reported separately since the collection and analyses of the data were made by different individuals. - 29 -