From inspection of Table 2 the following conclusions are made. There were measurable amounts of radioactivity in all the pre-shot samples, especially those from Bogombogo. For similar areas, the post shot samples were more radioactive than the pre-test samples by 200-300 times. The post shot samples from Igurin were higher than those at Rigili, Aaraanbiru and Runit, which were closer to the shot island. Usually the catch in the fine~meshed net was considerably more radioactive than the catch from a coarser-~meshed net for paired hauls from the same station, especially in the post shot samples. Some radioactivity was also found in the plankton preservative. The activity of the preservative from the Bogallua collection that was filtered through No. 42 Whatman paper was 10,000 d/m/cc as compared to 11,000 a/m/oc for the unfiltered sample. The plankton for the same sample was 100 times greater (1,100,000 a/m/g wet). The activity of the preservative suggests that some radioactive isotopes associated with the plankton are partly soluble in a 4 percent formalin solution or that some of the adsorbed particles are washed off the organisms. 4.3 Algae The algae collections included five species of blue-green Qlgae, 14 species of green, 3 species of brown, and 7 species of red algae. <A check list of species collected for assay is gZiven in the Appendix. Analysis by Area. Because of the paucity of samples and hon-randomness of sampling, the best evaluation of the data - 25 - od ‘ik IVS